[ChanhKien.org]<\/b><\/p>\n
Ng\u01b0\u1eddi \u0111o\u1ea1t gi\u1ea3i Nobel v\u1eadt l\u00fd Richard Feynman c\u00f3 c\u00e2u n\u00f3i n\u1ed5i ti\u1ebfng: \u201cT\u00f4i ngh\u0129 t\u00f4i c\u00f3 th\u1ec3 n\u00f3i m\u1ed9t c\u00e1ch ch\u1eafc ch\u1eafn r\u1eb1ng kh\u00f4ng c\u00f3 ai th\u1eadt s\u1ef1 hi\u1ec3u \u0111\u01b0\u1ee3c C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed!\u201d (\u201cI think I can safely say that nobody really understands quantum mechanics\u201d) Niels Bohr, m\u1ed9t ng\u01b0\u1eddi s\u00e1ng l\u1eadp kh\u00e1c c\u1ee7a Thuy\u1ebft l\u01b0\u1ee3ng t\u1eed, c\u0169ng n\u00f3i: \u201cN\u1ebfu ai kh\u00f4ng c\u1ea3m th\u1ea5y Thuy\u1ebft l\u01b0\u1ee3ng t\u1eed kh\u00f3 hi\u1ec3u th\u00ec ng\u01b0\u1eddi \u0111\u00f3 kh\u00f4ng hi\u1ec3u Thuy\u1ebft l\u01b0\u1ee3ng t\u1eed.\u201d (\u201cIf quantum mechanics hasn’t profoundly shocked you, you haven’t understood it yet.\u201d). C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed t\u1eeb l\u00fac ra \u0111\u1eddi \u0111\u00e3 ph\u1ee7 l\u00ean n\u00f3 m\u1ed9t l\u1edbp m\u00e0ng che, c\u00f2n b\u1ecb m\u00e2y m\u00f9 qu\u1ea5n quanh. B\u1ea3n th\u00e2n Erwin Schr\u00f6dinger, ng\u01b0\u1eddi \u0111\u00e3 s\u00e1ng l\u1eadp ra Ph\u01b0\u01a1ng tr\u00ecnh Schr\u00f6dinger n\u1ed5i ti\u1ebfng, c\u0169ng v\u00f4 c\u00f9ng b\u1ea5t m\u00e3n v\u1edbi nh\u1eefng lu\u1eadn gi\u1ea3i c\u1ee7a tr\u01b0\u1eddng ph\u00e1i Copenhagen v\u1ec1 H\u00e0m s\u00f3ng cho t\u1edbi t\u00ednh b\u1ea5t \u0111\u1ecbnh c\u1ee7a Tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp (ch\u1ed3ng ch\u1eadp). V\u00ec v\u1eady Schr\u00f6dinger \u0111\u00e3 thi\u1ebft l\u1eadp m\u1ed9t th\u00ed nghi\u1ec7m t\u01b0\u1edfng t\u01b0\u1ee3ng \u0111\u1ec3 ch\u1ebf nh\u1ea1o nh\u1eefng gi\u1ea3i th\u00edch n\u00e0y. \u00d4ng d\u00f9ng h\u00ecnh \u1ea3nh con m\u00e8o ho\u1eb7c s\u1ed1ng ho\u1eb7c ch\u1ebft \u0111\u1ec3 t\u1ef7 d\u1ee5 t\u00ednh ph\u1ea3n tr\u1ef1c quan v\u00e0 t\u00ednh b\u1ea5t \u0111\u1ecbnh trong lu\u1eadn gi\u1ea3i c\u1ee7a C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed, n\u1ebfu nh\u01b0 v\u1eady th\u00ec s\u1ebd d\u1eabn \u0111\u1ebfn m\u1ed9t k\u1ebft lu\u1eadn sai l\u1ea7m.<\/p>\n
Tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp l\u00e0 g\u00ec? V\u00ed d\u1ee5, con m\u00e8o \u0111ang \u1edf tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp c\u1ee7a s\u1ed1ng v\u00e0 ch\u1ebft (t\u1ee9c l\u00e0 c\u00f3 th\u1ec3 v\u1eeba s\u1ed1ng v\u1eeba ch\u1ebft), mu\u1ed1n bi\u1ebft th\u00ec ph\u1ea3i m\u1edf h\u1ed9p ra nh\u00ecn, t\u1ee9c l\u00e0 c\u1ea7n \u0111o l\u01b0\u1eddng, n\u1ebfu nh\u01b0 con m\u00e8o c\u00f2n s\u1ed1ng th\u00ec c\u00f3 ngh\u0129a l\u00e0 H\u00e0m s\u00f3ng c\u1ee7a Tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp \u0111\u00f3 \u0111\u00e3 s\u1ee5p \u0111\u1ed5 \u0111\u1ebfn tr\u1ea1ng th\u00e1i ri\u00eang c\u1ee7a s\u1ed1ng; ng\u01b0\u1ee3c l\u1ea1i, n\u00f3 \u0111\u00e3 s\u1ee5p \u0111\u1ed5 \u0111\u1ebfn tr\u1ea1ng th\u00e1i ri\u00eang c\u1ee7a ch\u1ebft. C\u00e1ch n\u00f3i lo\u1ea1n logic ki\u1ec3u \u2018v\u1eeba s\u1ed1ng v\u1eeba ch\u1ebft\u2019, \u2018kh\u00f4ng s\u1ed1ng kh\u00f4ng ch\u1ebft\u2019 n\u00e0y ch\u00ednh l\u00e0 c\u00e1ch c\u01a1 b\u1ea3n \u0111\u1ec3 gi\u1ea3i th\u00edch l\u01b0\u1ee3ng t\u1eed trong C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed. Tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp tr\u00e0o ph\u00fang qua h\u00ecnh \u1ea3nh con m\u00e8o c\u1ee7a Schr\u00f6dinger \u0111\u00e3 tr\u1edf th\u00e0nh m\u1ed9t kh\u00e1i ni\u1ec7m kinh \u0111i\u1ec3n c\u1ee7a C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed. \u0110\u1ed1i v\u1edbi t\u1ea5t c\u1ea3 nh\u1eefng s\u1ef1 vi\u1ec7c ch\u01b0a x\u00e1c \u0111\u1ecbnh \u0111\u1ec1u c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c nh\u1eadn d\u1ea1ng b\u1eb1ng tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp mang t\u00ednh x\u00e1c su\u1ea5t ng\u1eabu nhi\u00ean n\u00e0y. \u0110\u00e2y ch\u1ec9 l\u00e0 s\u1ef1 kh\u1edfi \u0111\u1ea7u, nh\u1eefng \u0111i\u1ec1u k\u1ef3 d\u1ecb c\u00f2n \u1edf ph\u00eda sau.<\/p>\n
Tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp l\u00e0 b\u00ed \u1ea9n l\u1edbn nh\u1ea5t c\u1ee7a C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed, hi\u1ec7n t\u01b0\u1ee3ng Tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp l\u01b0\u1ee3ng t\u1eed c\u0169ng l\u00e0 ng\u1ecdn ngu\u1ed3n kh\u01a1i m\u00e0u c\u1ea3m gi\u00e1c th\u1ea7n b\u00ed, \u0111\u1ed3ng th\u1eddi c\u0169ng d\u1eabn \u0111\u1ebfn \u1ea3o t\u01b0\u1edfng v\u00f4 t\u1eadn c\u1ee7a con ng\u01b0\u1eddi.<\/p>\n
N\u0103m 1927, t\u1ea1i h\u1ed9i ngh\u1ecb Solvay l\u1ea7n th\u1ee9 5 c\u1ee7a gi\u1edbi tinh anh trong l\u0129nh v\u1ef1c v\u1eadt l\u00fd h\u1ecdc \u0111\u00e3 n\u1ed5 ra cu\u1ed9c tranh lu\u1eadn n\u1ed5i ti\u1ebfng gi\u1eefa Bohr v\u00e0 Einstein. Hai nh\u00e0 v\u1eadt l\u00fd Albert Einstein v\u00e0 Niels Bohr l\u1ea7n l\u01b0\u1ee3t \u0111o\u1ea1t gi\u1ea3i Nobel V\u1eadt l\u00fd n\u0103m 1921 v\u00e0 1922 nh\u1edd gi\u1ea3i quy\u1ebft v\u1ea5n \u0111\u1ec1 Hi\u1ec7u \u1ee9ng quang \u0111i\u1ec7n v\u00e0 M\u00f4 h\u00ecnh nguy\u00ean t\u1eed l\u01b0\u1ee3ng t\u1eed h\u00f3a. Cu\u1ed9c tranh lu\u1eadn c\u1ee7a h\u1ecd ch\u1ee7 y\u1ebfu xoay quanh l\u00fd thuy\u1ebft n\u1ec1n t\u1ea3ng v\u00e0 ph\u01b0\u01a1ng di\u1ec7n t\u01b0 t\u01b0\u1edfng tri\u1ebft h\u1ecdc c\u1ee7a C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed. Einstein lu\u00f4n gi\u1eef th\u00e1i \u0111\u1ed9 ho\u00e0i nghi \u0111\u1ed1i v\u1edbi Thuy\u1ebft l\u01b0\u1ee3ng t\u1eed v\u00e0 nh\u1eefng gi\u1ea3i th\u00edch c\u1ee7a ph\u00e1i Bohr, v\u00ec v\u1eady \u00f4ng n\u00f3i: \u201cC\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed ch\u1eafc ch\u1eafn ho\u00e0nh tr\u00e1ng h\u00f9ng v\u0129. Nh\u01b0ng m\u1ed9t gi\u1ecdng n\u00f3i b\u00ean trong m\u00e1ch b\u1ea3o t\u00f4i r\u1eb1ng \u0111\u00f3 v\u1eabn ch\u01b0a ph\u1ea3i l\u00e0 \u0111i\u1ec1u ch\u00e2n th\u1eadt. L\u00fd thuy\u1ebft n\u00e0y gi\u1ea3i th\u00edch r\u1ea5t nhi\u1ec1u nh\u01b0ng kh\u00f4ng d\u1eabn d\u1eaft ch\u00fang ta \u0111\u1ebfn g\u1ea7n h\u01a1n v\u1edbi nh\u1eefng b\u00ed \u1ea9n c\u1ee7a \u201cTh\u01b0\u1ee3ng \u0111\u1ebf\u201d. D\u00f9 sao \u0111i n\u1eefa, t\u00f4i v\u1eabn tin t\u01b0\u1edfng s\u00e2u s\u1eafc r\u1eb1ng Th\u01b0\u1ee3ng \u0111\u1ebf kh\u00f4ng ch\u01a1i tr\u00f2 x\u00fac x\u1eafc.\u201d (\u201cQuantum mechanics is certainly imposing. But an inner voice tells me that it is not yet the real thing. The theory says a lot, but does not really bring us any closer to the secret of the ‘old one’. I, at any rate, am convinced that He does not throw dice.\u201d) \u0110\u1ed3ng th\u1eddi Einstein \u0111\u1ec1 xu\u1ea5t h\u1ebft th\u00ed nghi\u1ec7m t\u01b0\u1edfng t\u01b0\u1ee3ng n\u00e0y \u0111\u1ebfn th\u00ed nghi\u1ec7m t\u01b0\u1edfng t\u01b0\u1ee3ng kh\u00e1c, nh\u1eb1m m\u1ee5c \u0111\u00edch ch\u1ee9ng minh t\u00ednh kh\u00f4ng ho\u00e0n ch\u1ec9nh c\u1ee7a Thuy\u1ebft l\u01b0\u1ee3ng t\u1eed v\u00e0 c\u00e1c lu\u1eadn gi\u1ea3i ch\u00ednh th\u1ed1ng. \u0110\u00f3 l\u00e0 v\u00ec Einstein lu\u00f4n ki\u00ean tr\u00ec c\u1ed1 th\u1ee7 t\u01b0 t\u01b0\u1edfng tri\u1ebft h\u1ecdc c\u1ed5 \u0111i\u1ec3n v\u00e0 quan ni\u1ec7m nh\u00e2n qu\u1ea3, cho r\u1eb1ng: M\u1ed9t l\u00fd thuy\u1ebft v\u1eadt l\u00fd ho\u00e0n ch\u1ec9nh c\u1ea7n ph\u1ea3i c\u00f3 t\u00ednh x\u00e1c \u0111\u1ecbnh, t\u00ednh th\u1ef1c t\u1ea1i v\u00e0 t\u00ednh \u0111\u1ecbnh x\u1ee9 (hay t\u00ednh c\u1ee5c b\u1ed9). Tuy nhi\u00ean, Nguy\u00ean l\u00fd b\u1ea5t \u0111\u1ecbnh (Uncertainty principle) do Werner Heisenberg \u0111\u1ec1 xu\u1ea5t n\u0103m 1927 l\u1ea1i cho r\u1eb1ng v\u1ecb tr\u00ed v\u00e0 \u0111\u1ed9ng l\u01b0\u1ee3ng c\u1ee7a c\u00e1c h\u1ea1t kh\u00f4ng th\u1ec3 n\u00e0o l\u00e0 c\u00f9ng x\u00e1c \u0111\u1ecbnh; C\u00e1i g\u1ecdi l\u00e0 t\u00ednh th\u1ef1c t\u1ea1i l\u00e0 ch\u1ec9 s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a v\u1eadt ch\u1ea5t trong th\u1ebf gi\u1edbi kh\u00e1ch quan kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o vi\u1ec7c quan s\u00e1t; T\u00ednh \u0111\u1ecbnh x\u1ee9 l\u00e0 n\u00f3i m\u1ed9t s\u1ef1 ki\u1ec7n x\u1ea3y ra \u1edf m\u1ed9t \u0111i\u1ec3m xa x\u00f4i n\u00e0o \u0111\u00f3 kh\u00f4ng th\u1ec3 ngay l\u1eadp t\u1ee9c \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn m\u1ed9t \u0111i\u1ec3m kh\u00e1c. N\u00f3i c\u00e1ch kh\u00e1c, Einstein cho r\u1eb1ng t\u00edn hi\u1ec7u kh\u00f4ng th\u1ec3 \u0111\u01b0\u1ee3c truy\u1ec1n \u0111i nhanh h\u01a1n t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng.<\/p>\n
Tuy nhi\u00ean, hi\u1ec7u \u1ee9ng V\u01b0\u1edbng v\u00edu l\u01b0\u1ee3ng t\u1eed d\u01b0\u1eddng nh\u01b0 \u0111\u00e3 l\u1eadt ng\u01b0\u1ee3c gi\u1ea3 thuy\u1ebft c\u1ee7a Einstein, th\u1ec3 hi\u1ec7n ra m\u1ed9t s\u1ed1 \u0111i\u1ec1u mang t\u00ednh phi \u0111\u1ecbnh x\u1ee9 (b\u1ea5t c\u1ee5c b\u1ed9). N\u0103m 1935, Einstein v\u00e0 hai \u0111\u1ed3ng nghi\u1ec7p c\u1ee7a \u00f4ng c\u00f9ng vi\u1ebft lu\u1eadn v\u0103n \u201cS\u1ef1 m\u00f4 t\u1ea3 C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed \u0111\u1ed1i v\u1edbi t\u00ednh th\u1ef1c t\u1ea1i v\u1eadt l\u00fd c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c coi l\u00e0 ho\u00e0n ch\u1ec9nh kh\u00f4ng?\u201d (\u201cCan Quantum-Mechanical Description of Physical Reality Be Considered Complete?\u201d) c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 Ngh\u1ecbch l\u00fd EPR (EPR paradox), trong \u0111\u00f3 ch\u1ec9 ra r\u1eb1ng C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed kh\u00f4ng th\u1ec3 \u0111\u01b0a ra m\u00f4 t\u1ea3 ho\u00e0n ch\u1ec9nh v\u1ec1 t\u00ednh th\u1ef1c t\u1ea1i c\u1ee7a s\u1ef1 ki\u1ec7n (hi\u1ec7n t\u01b0\u1ee3ng) v\u1eadt l\u00fd, \u0111\u1ed3ng th\u1eddi tin t\u01b0\u1edfng r\u1eb1ng c\u00f3 th\u1ec3 t\u1ed3n t\u1ea1i m\u1ed9t l\u00fd thuy\u1ebft ho\u00e0n ch\u1ec9nh nh\u01b0 v\u1eady. Nh\u01b0ng trong thuy\u1ebft l\u01b0\u1ee3ng t\u1eed, \u0111\u1ed1i v\u1edbi s\u1ef1 ki\u1ec7n v\u1eadt l\u00fd li\u00ean \u0111\u1edbi t\u1ea1i hai khu v\u1ef1c c\u00e1ch xa nhau, vi\u1ec7c \u0111o \u0111\u01b0\u1ee3c tr\u1ea1ng th\u00e1i c\u1ee7a m\u1ed9t trong hai s\u1ebd khi\u1ebfn H\u00e0m s\u00f3ng c\u1ee7a c\u1ea3 hai \u0111\u1ed3ng th\u1eddi s\u1ee5p \u0111\u1ed5, t\u1ee9c l\u00e0 trong V\u01b0\u1edbng m\u1eafc l\u01b0\u1ee3ng t\u1eed n\u1ebfu \u0111o \u0111\u01b0\u1ee3c tr\u1ea1ng th\u00e1i c\u1ee7a m\u1ed9t h\u1ea1t th\u00ec s\u1ebd bi\u1ebft \u0111\u01b0\u1ee3c tr\u1ea1ng th\u00e1i c\u1ee7a h\u1ea1t c\u00f2n l\u1ea1i \u1edf c\u00e1ch r\u1ea5t xa kia. Einstein ch\u1ebf nh\u1ea1o \u0111\u00f3 l\u00e0 \u201cT\u00e1c \u0111\u1ed9ng ma qu\u00e1i t\u1eeb xa\u201d (spooky action at a distance) v\u00e0 d\u00f9ng \u0111i\u1ec1u n\u00e0y \u0111\u1ec3 ch\u1ee9ng minh C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed ch\u01b0a ho\u00e0n ch\u1ec9nh (Gi\u1ea3i th\u00edch: Einstein tin r\u1eb1ng kh\u00f4ng m\u1ed9t t\u00e1c \u0111\u1ed9ng n\u00e0o c\u1ee7a ph\u00e9p \u0111o l\u00ean h\u1ea1t th\u1ee9 nh\u1ea5t l\u1ea1i c\u00f3 th\u1ec3 ngay l\u1eadp t\u1ee9c \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn h\u1ea1t th\u1ee9 hai, v\u00ec \u0111i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 th\u00f4ng tin t\u00e1c \u0111\u1ed9ng c\u00f3 th\u1ec3 truy\u1ec1n nhanh h\u01a1n v\u1eadn t\u1ed1c \u00e1nh s\u00e1ng v\u00e0 nh\u01b0 v\u1eady n\u00f3 vi ph\u1ea1m Thuy\u1ebft t\u01b0\u01a1ng \u0111\u1ed1i h\u1eb9p.) Ch\u00ednh s\u1ef1 ‘S\u1ee5p \u0111\u1ed5 h\u00e0m s\u00f3ng’ – gi\u1ea3 thuy\u1ebft mang t\u00ednh bi\u1ec3u t\u01b0\u1ee3ng c\u1ee7a Lu\u1eadn gi\u1ea3i Copenhagen ch\u00ednh th\u1ed1ng C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed, l\u00e0 \u1ea9n d\u1ee5 c\u1ee7a \u201ct\u00e1c \u0111\u1ed9ng t\u1eeb xa\u201d v\u01b0\u1ee3t qu\u00e1 t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng, c\u0169ng \u0111\u1ed3ng th\u1eddi ph\u1ea3n \u00e1nh t\u00ednh phi \u0111\u1ecbnh x\u1ee9 c\u1ee7a l\u01b0\u1ee3ng t\u1eed.<\/p>\n
T\u1eeb ph\u01b0\u01a1ng di\u1ec7n th\u1ebf gi\u1edbi v\u1eadt ch\u1ea5t v\u0129 m\u00f4 tr\u00ean th\u1ebf gian, t\u00ednh th\u1ef1c t\u1ea1i v\u00e0 t\u00ednh \u0111\u1ecbnh x\u1ee9 l\u00e0 nguy\u00ean t\u1eafc nh\u1eadn th\u1ee9c \u0111\u01b0\u1ee3c h\u00ecnh th\u00e0nh trong qu\u00e1 tr\u00ecnh ph\u00e1t tri\u1ec3n khoa h\u1ecdc, n\u1ec1n t\u1ea3ng c\u1ee7a s\u1ef1 ph\u00e1t tri\u1ec3n khoa h\u1ecdc l\u00e0 ch\u1ee9ng c\u1ee9 x\u00e1c th\u1ef1c. C\u00e1c ph\u01b0\u01a1ng ph\u00e1p \u0111o l\u01b0\u1eddng khoa h\u1ecdc c\u0169ng l\u00e0 d\u00f9ng \u0111\u1ec3 nghi\u00ean c\u1ee9u nh\u1eefng s\u1ef1 v\u1eadt hi\u1ec7n t\u01b0\u1ee3ng \u0111\u00e3 nh\u1eadn th\u1ee9c \u0111\u01b0\u1ee3c, ph\u01b0\u01a1ng ph\u00e1p khoa h\u1ecdc k\u1ef9 thu\u1eadt hi\u1ec7n nay kh\u00f4ng c\u00f3 kh\u1ea3 n\u0103ng v\u00e0 \u0111i\u1ec1u ki\u1ec7n \u0111\u1ec3 th\u0103m d\u00f2 \u0111\u1ed9t ph\u00e1 th\u1eddi gian v\u00e0 kh\u00f4ng gian (th\u1eddi kh\u00f4ng). S\u1ef1 xu\u1ea5t hi\u1ec7n c\u1ee7a l\u01b0\u1ee3ng t\u1eed \u0111\u00e3 th\u00e1ch th\u1ee9c nh\u1eefng nh\u1eadn th\u1ee9c v\u00e0 quan \u0111i\u1ec3m tri\u1ebft h\u1ecdc ph\u1ed5 bi\u1ebfn c\u1ee7a con ng\u01b0\u1eddi, t\u1eeb \u0111\u00f3 m\u1edf ra con \u0111\u01b0\u1eddng kh\u00e1m ph\u00e1 th\u1ebf gi\u1edbi vi m\u00f4. L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 t\u00ecm hi\u1ec3u v\u00e0 kh\u00e1m ph\u00e1 th\u1ebf gi\u1edbi vi m\u00f4? Ernest Rutherford khi tr\u00ecnh b\u00e0y v\u1ec1 m\u00f4 h\u00ecnh nguy\u00ean t\u1eed \u0111\u00e3 n\u00f3i r\u1eb1ng \u0111\u00f3 gi\u1ed1ng nh\u01b0 m\u1ed9t H\u1ec7 M\u1eb7t Tr\u1eddi nh\u1ecf. Nh\u01b0 v\u1eady, n\u1ebfu nh\u00ecn t\u1eeb g\u00f3c \u0111\u1ed9 c\u1ee7a m\u1ed9t th\u1eddi kh\u00f4ng kh\u00e1c, li\u1ec7u m\u1ed9t l\u01b0\u1ee3ng t\u1eed ph\u1ea3i ch\u0103ng c\u0169ng l\u00e0 m\u1ed9t H\u1ec7 Ng\u00e2n H\u00e0 trong m\u1ed9t v\u0169 tr\u1ee5 vi m\u00f4?<\/p>\n
Trong l\u00fd Thuy\u1ebft l\u01b0\u1ee3ng t\u1eed, l\u01b0\u1ee3ng t\u1eed \u0111\u01b0\u1ee3c coi l\u00e0 nh\u1eefng h\u1ea1t c\u01a1 b\u1ea3n kh\u00f4ng th\u1ec3 ph\u00e2n chia, nh\u01b0ng n\u00f3 l\u1ea1i kh\u00f4ng \u0111\u01b0a ra \u0111\u01b0\u1ee3c mi\u00eau t\u1ea3 h\u00ecnh d\u1ea1ng r\u00f5 r\u00e0ng, tr\u1ef1c quan, m\u00e0 ch\u1ec9 s\u1eed d\u1ee5ng nh\u1eefng t\u00ednh to\u00e1n tr\u1eebu t\u01b0\u1ee3ng \u0111\u1ec3 bi\u1ec3u \u0111\u1ea1t h\u00ecnh th\u1ee9c v\u00e0 c\u00f2n bao b\u1ecdc n\u00f3 trong c\u00e1c h\u00e0m s\u00f3ng m\u00f9 m\u1edd, th\u00eam v\u00e0o \u0111\u00f3 l\u00e0 s\u1ef1 \u0111o l\u01b0\u1eddng \u0111\u00e3 tr\u1edf th\u00e0nh m\u1ed9t thu\u1ed9c t\u00ednh c\u01a1 b\u1ea3n kh\u00f4ng th\u1ec3 thi\u1ebfu c\u1ee7a l\u01b0\u1ee3ng t\u1eed. Sau khi \u0111\u01b0\u1ee3c \u0111o l\u01b0\u1eddng, th\u00ec h\u00e0m s\u00f3ng m\u00f4 t\u1ea3 tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp s\u1ebd s\u1ee5p \u0111\u1ed5 v\u1ec1 tr\u1ea1ng th\u00e1i ri\u00eang, v\u01b0\u1edbng m\u1eafc l\u01b0\u1ee3ng t\u1eed l\u1ea1i c\u0169ng s\u1ee5p \u0111\u1ed5 \u1edf kho\u1ea3ng c\u00e1ch xa, t\u1ed5ng h\u00f2a c\u00e1c \u0111i\u1ec1u \u0111\u00f3 \u0111\u01b0a \u0111\u1ebfn tr\u1ea1ng th\u00e1i th\u1ef1c s\u1ef1 c\u1ee7a l\u01b0\u1ee3ng t\u1eed. R\u1ed1t cu\u1ed9c khi\u1ebfn ng\u01b0\u1eddi ta kh\u00f3 c\u00f3 th\u1ec3 th\u1ef1c s\u1ef1 n\u1eafm b\u1eaft \u0111\u01b0\u1ee3c \u00fd ngh\u0129a tr\u1ecdng y\u1ebfu c\u1ee7a Thuy\u1ebft l\u01b0\u1ee3ng t\u1eed. Tr\u00ean th\u1ef1c t\u1ebf, m\u1ed9t l\u01b0\u1ee3ng t\u1eed c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c h\u00ecnh dung nh\u01b0 m\u1ed9t ‘h\u1ea1t \u0111\u00e1m m\u00e2y’ \u0111\u01b0\u1ee3c t\u1ea1o th\u00e0nh t\u1eeb t\u1eadp h\u1ee3p nh\u1eefng h\u1ea1t nh\u1ecf h\u01a1n, gi\u1ed1ng nh\u01b0 c\u00e1c electron quay quanh h\u1ea1t nh\u00e2n nguy\u00ean t\u1eed, \u0111\u1ed3ng th\u1eddi c\u0169ng n\u00f3 c\u0169ng t\u1ef1 xoay quanh n\u00f3 v\u00e0 ti\u1ebfn \u0111\u1ed9ng (chuy\u1ec3n \u0111\u1ed9ng thay \u0111\u1ed5i h\u01b0\u1edbng c\u1ee7a tr\u1ee5c t\u1ef1 quay). Trong m\u1ed9t v\u00f2ng xoay chuy\u1ec3n, tr\u1ee5c t\u1ef1 chuy\u1ec3n nghi\u00eang tr\u00e1i, nghi\u00eang ph\u1ea3i, nghi\u00eang tr\u01b0\u1edbc, nghi\u00eang sau trong chuy\u1ec3n \u0111\u1ed9ng ti\u1ebfn \u0111\u1ed9ng mang t\u00ednh chu k\u1ef3, th\u1ec3 hi\u1ec7n dao \u0111\u1ed9ng mang t\u00ednh chu k\u1ef3 c\u1ee7a b\u1ee9c x\u1ea1 n\u0103ng l\u01b0\u1ee3ng theo m\u1ed9t ph\u01b0\u01a1ng \u0111\u1eb7c \u0111\u1ecbnh n\u00e0o \u0111\u00f3, ch\u1eb3ng h\u1ea1n nh\u01b0 chu k\u1ef3 h\u00ecnh sin. ‘H\u1ea1t \u0111\u00e1m m\u00e2y’ th\u1ec3 hi\u1ec7n c\u00e1c \u0111\u1eb7c tr\u01b0ng c\u01a1 b\u1ea3n mang t\u00ednh h\u1ea1t c\u1ee7a l\u01b0\u1ee3ng t\u1eed, trong khi ‘t\u00ednh ch\u1ea5t s\u00f3ng’ ch\u1ec9 l\u00e0 m\u1ed9t h\u00ecnh th\u1ee9c bi\u1ec3u hi\u1ec7n c\u1ee7a b\u1ee9c x\u1ea1 n\u0103ng l\u01b0\u1ee3ng g\u00e2y ra do s\u1ef1 t\u1ef1 xoay, ti\u1ebfn \u0111\u1ed9ng v\u00e0 chuy\u1ec3n \u0111\u1ed9ng d\u1ecdc theo qu\u1ef9 \u0111\u1ea1o. M\u00f4 h\u00ecnh c\u1ee7a t\u00ednh th\u1ed1ng nh\u1ea5t s\u00f3ng h\u1ea1t n\u00e0y so v\u1edbi s\u1ef1 tr\u1eebu t\u01b0\u1ee3ng c\u1ee7a H\u00e0m s\u00f3ng th\u00ec tr\u1ef1c quan h\u01a1n, c\u0169ng d\u1ec5 hi\u1ec3u h\u01a1n, \u0111\u1ed3ng th\u1eddi c\u0169ng d\u1ec5 \u1ee9ng \u200b\u200bd\u1ee5ng v\u00e0 x\u00e1c minh h\u01a1n khi ph\u00e2n t\u00edch v\u1ea5n \u0111\u1ec1. \u0110\u1ed1i v\u1edbi c\u00e1c t\u00ecnh hu\u1ed1ng ph\u1ee9c t\u1ea1p kh\u00e1c nhau xu\u1ea5t hi\u1ec7n trong khi \u1ee9ng d\u1ee5ng, m\u1ed7i ng\u01b0\u1eddi \u0111\u1ec1u c\u00f3 th\u1ec3 t\u1eeb c\u1ea3m gi\u00e1c tr\u1ef1c quan cho \u0111\u1ebfn logic l\u00fd t\u00ednh m\u00e0 ti\u1ebfn h\u00e0nh ph\u00e2n t\u00edch th\u00f4ng su\u1ed1t nh\u1ea5t qu\u00e1n, c\u00e1c hi\u1ec7n t\u01b0\u1ee3ng v\u00e0 v\u1ea5n \u0111\u1ec1 c\u01a1 ch\u1ebf kh\u00f3 gi\u1ea3i trong c\u00e1c th\u00ed nghi\u1ec7m C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed c\u0169ng s\u1ebd ti\u00eau m\u1ea5t kh\u00f4ng c\u1ea7n gi\u1ea3i th\u00edch.<\/p>\n
Khi con ng\u01b0\u1eddi kh\u00f4ng th\u1ec3 t\u00ecm th\u1ea5y l\u1ed1i tho\u00e1t trong Lu\u1eadn gi\u1ea3i Copenhagen ch\u00ednh th\u1ed1ng, Lu\u1eadn gi\u1ea3i \u0110a th\u1ebf gi\u1edbi c\u1ee7a C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed b\u1eaft \u0111\u1ea7u l\u1ecdt v\u00e0o t\u1ea7m ng\u1eafm c\u1ee7a h\u1ecd: (Theo \u0111\u00f3, trong th\u00ed nghi\u1ec7m t\u01b0\u1edfng t\u01b0\u1ee3ng c\u1ee7a Schr\u00f6dinger), v\u00e0o l\u00fac ng\u01b0\u1eddi quan s\u00e1t m\u1edf chi\u1ebfc h\u1ed9p, ng\u01b0\u1eddi quan s\u00e1t v\u00e0 con m\u00e8o s\u1ebd x\u1ea3y ra ‘v\u01b0\u1edbng m\u1eafc’. Do \u0111\u00f3, tr\u1ea1ng th\u00e1i c\u1ee7a ng\u01b0\u1eddi quan s\u00e1t \u0111\u1ed1i \u1ee9ng v\u1edbi tr\u1ea1ng th\u00e1i s\u1ed1ng v\u00e0 tr\u1ea1ng th\u00e1i ch\u1ebft c\u1ee7a con m\u00e8o h\u00ecnh th\u00e0nh c\u00e1c tr\u1ea1ng th\u00e1i ri\u00eang bi\u1ec7t; \u201cm\u00e8o ch\u1ebft\u201d ho\u1eb7c \u201cm\u00e8o s\u1ed1ng\u201d \u0111\u1ec1u l\u00e0 m\u1ed9t ph\u1ea7n c\u1ee7a v\u0169 tr\u1ee5 song song, \u0111\u1ec1u l\u00e0 t\u1ed5ng h\u00f2a c\u1ee7a t\u1ea5t c\u1ea3 c\u00e1c v\u0169 tr\u1ee5 song song (t\u1ee9c l\u00e0 con m\u00e8o c\u00f3 th\u1ec3 s\u1ed1ng trong v\u0169 tr\u1ee5 n\u00e0y v\u00e0 ch\u1ebft trong v\u0169 tr\u1ee5 kh\u00e1c t\u00f9y theo ng\u01b0\u1eddi quan s\u00e1t). Th\u1ea5y \u0111\u01b0\u1ee3c l\u1eddi gi\u1ea3i th\u00edch m\u01a1 h\u1ed3 nh\u01b0 th\u1ebf n\u00e0y th\u00ec c\u00f2n c\u00f3 th\u1ec3 n\u00f3i g\u00ec n\u1eefa?<\/p>\n
\u0110\u1ec3 tr\u1ea3 l\u1eddi nh\u1eefng ch\u1ea5t v\u1ea5n c\u1ee7a Einstein, c\u00e1c nh\u00e0 v\u1eadt l\u00fd \u0111\u00e3 ti\u1ebfn h\u00e0nh ch\u1ee9ng minh t\u00ednh phi \u0111\u1ecbnh x\u1ee9 c\u1ee7a C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed th\u00f4ng qua c\u00e1c th\u00ed nghi\u1ec7m ch\u1ee9ng minh B\u1ea5t \u0111\u1eb3ng th\u1ee9c Bell b\u1ecb vi ph\u1ea1m, trong m\u1ea5y th\u1eadp ni\u00ean qua, c\u00e1c nh\u00e0 v\u1eadt l\u00fd \u0111\u00e3 th\u1ef1c hi\u1ec7n r\u1ea5t nhi\u1ec1u th\u00ed nghi\u1ec7m li\u00ean quan. Tr\u1ea1ng th\u00e1i c\u1ee7a hai photon v\u01b0\u1edbng m\u1eafc l\u01b0\u1ee3ng t\u1eed \u0111\u01b0\u1ee3c \u0111o ng\u1eabu nhi\u00ean \u1edf hai khu v\u1ef1c ri\u00eang bi\u1ec7t n\u1eb1m ngo\u00e0i kh\u1ea3 n\u0103ng truy\u1ec1n t\u00edn hi\u1ec7u v\u1edbi t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng. K\u1ebft qu\u1ea3 ch\u1ee9ng minh \u0111\u01b0\u1ee3c m\u1ed1i li\u00ean h\u1ec7 phi \u0111\u1ecbnh x\u1ee9 c\u1ee7a V\u01b0\u1edbng m\u1eafc l\u01b0\u1ee3ng t\u1eed, th\u00f4ng qua \u0111\u00f3 ch\u1ee9ng minh t\u00ednh ho\u00e0n ch\u1ec9nh c\u1ee7a C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed. Gi\u1ea3i Nobel V\u1eadt l\u00fd n\u0103m 2022 \u0111\u01b0\u1ee3c trao cho m\u1ed9t lo\u1ea1t c\u00f4ng tr\u00ecnh th\u1ef1c nghi\u1ec7m ch\u1ee9ng minh B\u1ea5t \u0111\u1eb3ng th\u1ee9c Bell b\u1ecb vi ph\u1ea1m, t\u1ee9c l\u00e0 s\u1eed d\u1ee5ng tr\u1ea1ng th\u00e1i v\u01b0\u1edbng m\u1eafc c\u1ee7a hai photon \u0111\u1ec3 ki\u1ec3m tra Bi\u1ebfn th\u1ec3 (phi\u00ean b\u1ea3n) CHSH c\u1ee7a B\u1ea5t \u0111\u1eb3ng th\u1ee9c Bell. Trong th\u00ed nghi\u1ec7m, tr\u1ea1ng th\u00e1i ph\u00e2n c\u1ef1c ngang v\u00e0 tr\u1ea1ng th\u00e1i ph\u00e2n c\u1ef1c d\u1ecdc c\u1ee7a c\u00e1c photon \u0111\u01b0\u1ee3c \u0111o ng\u1eabu nhi\u00ean v\u00e0 k\u1ebft qu\u1ea3 \u0111\u01b0\u1ee3c so s\u00e1nh, cho th\u1ea5y t\u00ednh t\u01b0\u01a1ng quan trong h\u01b0\u1edbng ph\u00e2n c\u1ef1c c\u1ee7a hai photon v\u01b0\u1edbng m\u1eafc.<\/p>\n
B\u1edfi v\u00ec l\u01b0\u1ee3ng t\u1eed l\u00e0 th\u00e0nh ph\u1ea7n c\u1ee7a kh\u00f4ng gian vi m\u00f4, n\u1ebfu mu\u1ed1n th\u1ef1c s\u1ef1 nh\u1eadn th\u1ee9c \u0111\u01b0\u1ee3c \u0111\u1eb7c t\u00ednh c\u1ee7a n\u00f3, c\u1ea7n ph\u1ea3i ti\u1ebfn nh\u1eadp v\u00e0o t\u1ea7ng di\u1ec7n t\u01b0\u01a1ng \u1ee9ng c\u1ee7a h\u1ea1t \u0111\u00f3 trong th\u1ebf gi\u1edbi vi m\u00f4, s\u1eed d\u1ee5ng ph\u01b0\u01a1ng th\u1ee9c t\u01b0 duy v\u00e0 ph\u01b0\u01a1ng th\u1ee9c quan s\u00e1t th\u1ebf gi\u1edbi vi m\u00f4 \u0111\u1ec3 nh\u1eadn th\u1ee9c. C\u00e1c \u0111\u1eb7c t\u00ednh c\u1ee7a l\u01b0\u1ee3ng t\u1eed kh\u00e1c bi\u1ec7t r\u1ea5t l\u1edbn so v\u1edbi c\u00e1c \u0111\u1eb7c t\u00ednh bi\u1ec3u hi\u1ec7n trong kh\u00f4ng gian v\u0129 m\u00f4 v\u00e0 v\u1eadt th\u1ec3 v\u0129 m\u00f4, v\u00ed d\u1ee5 n\u00f3i r\u1eb1ng, l\u01b0\u1ee3ng t\u1eed kh\u00f4ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng, kh\u00f4ng c\u00f3 qu\u00e1n t\u00ednh, v.v. v\u1eady n\u00ean r\u1ea5t kh\u00f3 d\u00f9ng l\u00fd thuy\u1ebft c\u1ee7a C\u01a1 h\u1ecdc c\u1ed5 \u0111i\u1ec3n \u0111\u1ec3 m\u00f4 t\u1ea3 C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed. Khi m\u1ed9t photon b\u1eafn ra l\u1eadp t\u1ee9c \u0111\u1ea1t \u0111\u1ebfn t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng m\u00e0 kh\u00f4ng c\u1ea7n b\u1ea5t k\u1ef3 qu\u00e1 tr\u00ecnh gia t\u1ed1c n\u00e0o, v\u00e0 kh\u00f4ng b\u1ecb m\u1ea5t \u0111\u1ed9ng l\u01b0\u1ee3ng hay gi\u1ea3m t\u1ed1c \u0111\u1ed9 khi g\u1eb7p s\u1ef1 ph\u1ea3n x\u1ea1; khi xuy\u00ean qua tinh th\u1ec3 l\u01b0\u1ee1ng chi\u1ebft (tinh th\u1ec3 g\u00e2y ra kh\u00fac x\u1ea1 \u00e1nh s\u00e1ng) th\u00ec t\u1ed1c \u0111\u1ed9 s\u1ebd gi\u1ea3m, nh\u01b0ng sau khi \u0111i qua th\u00ec kh\u00f4ng c\u1ea7n l\u1ef1c t\u00e1c \u0111\u1ed9ng m\u00e0 l\u1eadp t\u1ee9c kh\u00f4i ph\u1ee5c l\u1ea1i t\u1ed1c \u0111\u1ed9 ban \u0111\u1ea7u. Ph\u1ea3i ch\u0103ng s\u1ef1 xu\u1ea5t hi\u1ec7n c\u1ee7a l\u01b0\u1ee3ng t\u1eed \u00e1m th\u1ecb r\u1eb1ng nh\u1eefng g\u00ec m\u00e0 C\u01a1 h\u1ecdc c\u1ed5 \u0111i\u1ec3n c\u1ee7a ch\u00fang ta tuy\u00ean b\u1ed1 kh\u00f4ng ph\u1ea3i l\u00e0 thu\u1ed9c t\u00ednh b\u1ea3n ch\u1ea5t c\u1ee7a c\u00e1c v\u1eadt th\u1ec3 trong v\u0169 tr\u1ee5?<\/p>\n
C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed v\u1eabn s\u1eed d\u1ee5ng c\u00e1c kh\u00e1i ni\u1ec7m c\u01a1 s\u1edf c\u1ee7a C\u01a1 h\u1ecdc c\u1ed5 \u0111i\u1ec3n \u0111\u1ec3 m\u00f4 t\u1ea3 l\u01b0\u1ee3ng t\u1eed, v\u00ed d\u1ee5 nh\u01b0: B\u1ea3o to\u00e0n Momen \u0111\u1ed9ng l\u01b0\u1ee3ng trong tr\u01b0\u1eddng h\u1ee3p xoay h\u01b0\u1edbng l\u00ean v\u00e0 xoay h\u01b0\u1edbng xu\u1ed1ng (spin up v\u00e0 spin down), v.v.. Nhi\u1ec1u k\u1ebft qu\u1ea3 th\u00ed nghi\u1ec7m c\u00f3 t\u00e1c d\u1ee5ng nh\u1eafc nh\u1edf ch\u00fang ta r\u1eb1ng trong qu\u00e1 tr\u00ecnh lan truy\u1ec1n th\u00ec h\u00ecnh th\u00e1i c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng t\u1ef1 xoay v\u00e0 chuy\u1ec3n \u0111\u1ed9ng ti\u1ebfn \u0111\u1ed9ng c\u1ee7a l\u01b0\u1ee3ng t\u1eed kh\u00f4ng b\u1ecb \u1ea3nh h\u01b0\u1edfng b\u1edfi c\u00e1c y\u1ebfu t\u1ed1 kh\u00e1c, ph\u01b0\u01a1ng c\u1ee7a m\u1eb7t ph\u1eb3ng qu\u1ef9 \u0111\u1ea1o v\u00e0 chu k\u1ef3 ti\u1ebfn \u0111\u1ed9ng v\u00e0 chu k\u1ef3 chuy\u1ec3n \u0111\u1ed9ng d\u1ecdc theo qu\u1ef9 \u0111\u1ea1o c\u00f3 th\u1ec3 thay \u0111\u1ed5i. V\u00ed d\u1ee5, khi photon xuy\u00ean qua m\u1ed9t tinh th\u1ec3 l\u01b0\u1ee1ng chi\u1ebft nh\u01b0 canxit s\u1ebd x\u1ea3y ra s\u1ef1 ph\u00e2n c\u1ef1c theo ph\u01b0\u01a1ng ngang v\u00e0 ph\u00e2n c\u1ef1c theo ph\u01b0\u01a1ng d\u1ecdc, t\u1ea7n s\u1ed1 v\u00e0 b\u01b0\u1edbc s\u00f3ng c\u0169ng s\u1ebd thay \u0111\u1ed5i, nh\u01b0ng h\u00ecnh th\u00e1i c\u1ee7a chuy\u1ec3n \u0111\u1ed9ng t\u1ef1 xoay v\u00e0 ti\u1ebfn \u0111\u1ed9ng c\u1ee7a photon c\u00f3 th\u1ec3 kh\u00f4ng thay \u0111\u1ed5i. V\u00ec v\u1eady, ph\u01b0\u01a1ng ph\u00e2n c\u1ef1c c\u1ee7a hai \u0111\u01b0\u1eddng photon v\u01b0\u1edbng m\u1eafc n\u00e0y l\u00e0 ho\u00e0n to\u00e0n c\u00f3 th\u1ec3 d\u1ef1 \u0111o\u00e1n \u0111\u01b0\u1ee3c.<\/p>\n
Do \u0111\u00f3, t\u00ednh t\u01b0\u01a1ng quan \u0111\u1ed1i \u1ee9ng gi\u1eefa dao \u0111\u1ed9ng h\u01b0\u1edbng ngang v\u00e0 dao \u0111\u1ed9ng h\u01b0\u1edbng d\u1ecdc \u0111\u01b0\u1ee3c x\u00e1c minh khi ki\u1ec3m tra tr\u1ea1ng th\u00e1i c\u1ee7a hai photon v\u01b0\u1edbng v\u00edu \u0111\u01b0\u1ee3c \u0111o trong th\u00ed nghi\u1ec7m, ch\u1ec9 l\u00e0 m\u1ed9t \u0111\u1eb7c tr\u01b0ng v\u1ed1n c\u00f3 c\u1ee7a tia o v\u00e0 tia e (sinh ra do ph\u00e2n c\u1ef1c) truy\u1ec1n theo hai h\u01b0\u1edbng kh\u00e1c nhau, ch\u00fang c\u0169ng c\u00f3 m\u1ed1i li\u00ean h\u1ec7 giao thoa v\u1edbi c\u00e1c c\u1eb7p photon kh\u00e1c kh\u00f4ng? Hai photon trong c\u1eb7p photon v\u01b0\u1edbng m\u1eafc c\u0169ng c\u00f3 th\u1ec3 l\u00e0 do m\u1ed9t ‘\u0111\u00e1m m\u00e2y h\u1ea1t’ ph\u00e2n c\u1eaft th\u00e0nh, c\u00f3 c\u00f9ng \u0111\u1eb7c \u0111i\u1ec3m chuy\u1ec3n \u0111\u1ed9ng t\u1ef1 xoay, ti\u1ebfn \u0111\u1ed9ng v\u00e0 tr\u1ea1ng th\u00e1i pha, c\u00f3 \u0111i\u1ec1u l\u00e0 ch\u1ec9 s\u1ed1 kh\u00fac x\u1ea1 kh\u00e1c nhau khi\u1ebfn cho b\u01b0\u1edbc s\u00f3ng v\u00e0 t\u1ea7n s\u1ed1 c\u1ee7a ch\u00fang c\u00f3 s\u1ef1 x\u00ea d\u1ecbch kh\u00e1c nhau. N\u1ebfu m\u1ed9t b\u1ea3n ph\u00e2n c\u1ef1c \u0111\u01b0\u1ee3c \u0111\u1eb7t tr\u00ean m\u1ed9t trong hai \u0111\u01b0\u1eddng \u0111i c\u1ee7a photon \u0111\u1ec3 l\u00e0m l\u1ec7ch m\u1eb7t ph\u1eb3ng dao \u0111\u1ed9ng c\u1ee7a n\u00f3 (m\u1eb7t ph\u1eb3ng qu\u1ef9 \u0111\u1ea1o t\u1ef1 quay) theo m\u1ed9t g\u00f3c n\u00e0o \u0111\u00f3 th\u00ec li\u1ec7u l\u00fac n\u00e0y ch\u00fang c\u00f3 c\u00f2n \u1edf tr\u1ea1ng th\u00e1i v\u01b0\u1edbng m\u1eafc kh\u00f4ng? T\u1eeb \u0111\u00f3 c\u00f3 th\u1ec3 th\u1ea5y r\u1eb1ng, n\u1ebfu kh\u00f4ng t\u1ed3n t\u1ea1i s\u1ee5p \u0111\u1ed5 h\u00e0m s\u00f3ng do \u201ct\u00e1c d\u1ee5ng ma qu\u00e1i t\u1eeb xa\u201d, kh\u00e1i ni\u1ec7m \u2018v\u01b0\u1edbng m\u1eafc\u2019 ch\u1ec9 ch\u1ee9ng minh \u0111\u01b0\u1ee3c tr\u1ea1ng th\u00e1i ban \u0111\u1ea7u khi photon \u0111\u01b0\u1ee3c ph\u00f3ng ra l\u00e0 m\u1ed9t photon dao \u0111\u1ed9ng theo h\u01b0\u1edbng ngang v\u00e0 c\u00e1i kia dao \u0111\u1ed9ng theo h\u01b0\u1edbng d\u1ecdc m\u00e0 th\u00f4i, C\u00f3 ch\u1ed7 n\u00e0o cho th\u1ea5y n\u00f3 ph\u1ea3n \u00e1nh \u0111\u1eb7c t\u00ednh phi \u0111\u1ecbnh x\u1ee9? C\u00f3 g\u00ec kh\u00e1c bi\u1ec7t so v\u1edbi hai photon \u0111\u1ed9c l\u1eadp?<\/p>\n
V\u00ec v\u1eady m\u1edbi n\u00f3i, c\u01a1 \u0111i\u1ec3m c\u1ee7a vi\u1ec7c t\u00ednh li\u00ean \u0111\u1edbi trong V\u01b0\u1edbng m\u1eafc l\u01b0\u1ee3ng t\u1eed \u0111\u01b0a ng\u01b0\u1eddi ta v\u00e0o nh\u1eefng \u1ea3o m\u1ed9ng v\u00f4 t\u1eadn l\u00e0 m\u1ed9t s\u1ed1 t\u00edn hi\u1ec7u c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c nh\u1eadn bi\u1ebft ho\u1eb7c truy\u1ec1n t\u1ea3i t\u1ee9c th\u1eddi ho\u1eb7c \u0111\u1ed3ng b\u1ed9, b\u1eaft \u0111\u1ea7u t\u1eeb th\u1eddi c\u1ee7a Bohr, c\u00e1c nh\u00e0 v\u1eadt l\u00fd \u0111\u00e3 c\u1ea9n th\u1eadn tr\u00e1nh n\u00e9 n\u00f3i v\u1ec1 v\u1ea5n \u0111\u1ec1 n\u00e0y. Th\u00ed nghi\u1ec7m ki\u1ec3m ch\u1ee9ng B\u1ea5t \u0111\u1eb3ng th\u1ee9c Bell ch\u1ec9 nh\u1eafm v\u00e0o t\u00ednh \u0111\u1ed1i \u1ee9ng c\u1ee7a ph\u01b0\u01a1ng ph\u00e2n c\u1ef1c c\u1ee7a hai photon r\u1ed3i sau \u0111\u00f3 m\u1edbi t\u1eadp trung nghi\u00ean c\u1ee9u t\u1edbi t\u00ednh ng\u1eabu nhi\u00ean, tuy nhi\u00ean, t\u00ednh \u0111\u1ed1i \u1ee9ng n\u00e0y l\u1ea1i l\u00e0 t\u00ednh ch\u1ea5t chung c\u1ee7a photon tr\u00ean hai \u0111\u01b0\u1eddng tia o v\u00e0 tia e sinh ra b\u1edfi l\u0103ng k\u00ednh ph\u00e2n c\u1ef1c Grant Thompson. Nguy\u00ean nh\u00e2n c\u1ee7a ngh\u1ecbch l\u00fd n\u00e0y l\u00e0 do lu\u1eadn gi\u1ea3i v\u1ec1 Tr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp v\u00e0 t\u00ednh b\u1ea5t \u0111\u1ecbnh c\u1ee7a m\u00f4 h\u00ecnh photon trong Thuy\u1ebft l\u01b0\u1ee3ng t\u1eed g\u00e2y ra. N\u00f3 c\u0169ng ph\u1ea3n \u00e1nh s\u1ef1 tranh ch\u1ea5p l\u1eabn nhau trong v\u1ea5n \u0111\u1ec1 n\u00e0y gi\u1eefa quan \u0111i\u1ec3m tri\u1ebft h\u1ecdc Ch\u1ee7 ngh\u0129a duy v\u1eadt c\u1ee7a C\u01a1 h\u1ecdc c\u1ed5 \u0111i\u1ec3n v\u00e0 ch\u1ee7 ngh\u0129a duy t\u00e2m c\u1ee7a C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed, t\u00ednh v\u1eadt ch\u1ea5t c\u1ee7a l\u01b0\u1ee3ng t\u1eed trong vai tr\u00f2 h\u1ea1t b\u1ecb m\u00e2y m\u00f9 c\u1ee7a \u00fd th\u1ee9c ch\u1ee7 quan \u0111ang bao tr\u00f9m. Tr\u00ean th\u1ef1c t\u1ebf, v\u1eadt ch\u1ea5t v\u00e0 tinh th\u1ea7n, nh\u1eefng th\u1ee9 t\u1ed3n t\u1ea1i v\u00e0 \u00fd th\u1ee9c v\u1ed1n d\u0129 c\u00f3 t\u00ednh th\u1ed1ng nh\u1ea5t. T\u1ea7ng t\u1ed3n t\u1ea1i v\u1eadt ch\u1ea5t trong th\u1ebf gi\u1edbi vi m\u00f4 m\u00e0 khoa h\u1ecdc c\u00f4ng ngh\u1ec7 c\u1ee7a con ng\u01b0\u1eddi v\u1eabn ch\u01b0a nh\u1eadn th\u1ee9c \u0111\u1ea7y \u0111\u1ee7 b\u1ecb coi l\u00e0 t\u1ea7ng tinh th\u1ea7n, v\u00e0 vi\u1ec7c thi\u1ebft l\u1eadp m\u00f4 h\u00ecnh s\u00f3ng h\u1ea1t c\u00f3 t\u00ednh th\u1ed1ng nh\u1ea5t c\u1ee7a l\u01b0\u1ee3ng t\u1eed c\u00f3 th\u1ec3 gi\u1ea3i th\u00edch nhi\u1ec1u nghi v\u1ea5n trong trong c\u00e1c hi\u1ec7n t\u01b0\u1ee3ng th\u1ef1c nghi\u1ec7m v\u00e0 l\u00fd lu\u1eadn m\u00e0 kh\u00f4ng th\u1ec3 gi\u1ea3i th\u00edch m\u1ed9t c\u00e1ch tr\u1ef1c quan trong c\u00e1c th\u00ed nghi\u1ec7m v\u1eadt l\u00fd.<\/p>\n
Ngo\u00e0i ra c\u00f2n m\u1ed9t lo\u1ea1i \u1ea3nh ba chi\u1ec1u k\u1ef9 thu\u1eadt s\u1ed1 h\u00ecnh \u1ea3nh hai photon \u0111\u01b0\u1ee3c g\u1ecdi m\u1ed9t c\u00e1ch ph\u00f3ng \u0111\u1ea1i l\u00e0 \u201cH\u00ecnh \u1ea3nh ma\u201d (Ghost imaging). Nguy\u00ean l\u00fd c\u1ee7a n\u00f3 c\u0169ng l\u1ee3i d\u1ee5ng \u0111\u1eb7c \u0111i\u1ec3m l\u00e0 c\u00e1c ph\u01b0\u01a1ng th\u1ee9c nh\u01b0 l\u0103ng k\u00ednh Grant Thompson t\u1ea1o ra g\u00f3c t\u01b0\u01a1ng \u0111\u1ed1i c\u1ed1 \u0111\u1ecbnh gi\u1eefa hai tia chi\u1ebft xu\u1ea5t o v\u00e0 e, v.v. Khi m\u1ed9t photon va \u0111\u1eadp v\u00e0o v\u1eadt th\u1ec3 \u0111\u01b0\u1ee3c m\u00e1y d\u00f2 ghi l\u1ea1i, c\u00f9ng l\u00fac \u0111\u00f3 t\u1ecda \u0111\u1ed9 hai chi\u1ec1u c\u1ee7a m\u1ed9t photon kh\u00e1c \u1edf m\u1ed9t v\u1ecb tr\u00ed kh\u00e1c c\u0169ng b\u1ecb ghi l\u1ea1i tr\u00ean m\u00e0n h\u00ecnh th\u0103m d\u00f2. Hai t\u1eadp h\u1ee3p d\u1eef li\u1ec7u t\u01b0\u01a1ng \u1ee9ng \u0111\u01b0\u1ee3c x\u1eed l\u00fd k\u1ef9 thu\u1eadt s\u1ed1 \u0111\u1ec3 t\u1ea1o ra h\u00ecnh \u1ea3nh. Tr\u00ean th\u1ef1c t\u1ebf, \u0111\u00e2y c\u0169ng l\u00e0 quan h\u1ec7 \u0111\u1ed1i \u1ee9ng c\u1ee7a c\u00e1c v\u1ecb tr\u00ed kh\u00f4ng gian \u0111\u01b0\u1ee3c h\u00ecnh th\u00e0nh b\u1edfi g\u00f3c c\u1ee7a hai photon \u0111i theo hai h\u01b0\u1edbng kh\u00e1c nhau, kh\u00f4ng ph\u1ea3i m\u1ed9t photon nh\u00ecn th\u1ea5y v\u1eadt th\u1ec3 v\u00e0 photon kia v\u1ebd ra h\u00ecnh \u1ea3nh m\u1ed9t c\u00e1ch \u201cth\u1ea7n giao c\u00e1ch c\u1ea3m\u201d.<\/p>\n
Ngo\u00e0i ra, tr\u00ean m\u1ea1ng Internet \u0111ang th\u1ea3o lu\u1eadn s\u00f4i n\u1ed5i \u0111i\u1ec1u qu\u00e1i d\u1ecb trong th\u00ed nghi\u1ec7m X\u00f3a b\u1ecf c\u00e1c l\u1ef1a ch\u1ecdn b\u1ecb tr\u00ec ho\u00e3n (Delayed-choice quantum eraser), b\u1ecb n\u00f3i th\u00e0nh: Quy\u1ebft \u0111\u1ecbnh c\u1ee7a hi\u1ec7n t\u1ea1i c\u00f3 th\u1ec3 thay \u0111\u1ed5i nh\u1eefng s\u1ef1 ki\u1ec7n \u0111\u00e3 x\u1ea3y ra ng\u00e0y h\u00f4m qua. Tr\u00ean th\u1ef1c t\u1ebf, ch\u00fang \u0111\u1ec1u c\u00f3 c\u00f9ng m\u1ed9t ki\u1ec3u thi\u1ebft k\u1ebf th\u00ed nghi\u1ec7m, \u0111\u00f3 l\u00e0 khi\u1ebfn cho th\u1eddi gian ch\u00eanh l\u1ec7ch gi\u1eefa hai n\u01a1i th\u0103m d\u00f2 nh\u1ecf h\u01a1n th\u1eddi gian \u0111\u1ec3 th\u00f4ng tin \u0111\u01b0\u1ee3c truy\u1ec1n v\u1edbi t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng gi\u1eefa hai n\u01a1i \u0111\u00f3, t\u1eeb \u0111\u00f3 hai photon kh\u00f4ng k\u1ecbp th\u1eddi truy\u1ec1n th\u00f4ng tin cho nhau. Tuy nhi\u00ean, kh\u00f4ng c\u00f3 l\u1eddi gi\u1ea3i th\u00edch h\u1ee3p l\u00fd n\u00e0o \u0111\u01b0\u1ee3c \u0111\u01b0a ra cho s\u1ef1 d\u1ecbch chuy\u1ec3n l\u1ec7ch pha c\u1ee7a c\u00e1c \u0111\u01b0\u1eddng cong \u03c0 khi x\u1eed l\u00fd d\u1eef li\u1ec7u t\u1eeb c\u00e1c m\u00e1y d\u00f2 kh\u00e1c nhau trong th\u00ed nghi\u1ec7m. Hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c l\u00fd gi\u1ea3i d\u1ec5 d\u00e0ng theo M\u00f4 h\u00ecnh t\u00ednh th\u1ed1ng nh\u1ea5t s\u00f3ng h\u1ea1t. L\u00fd do nh\u1eefng hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y kh\u00f4ng th\u1ec3 ph\u00e2n t\u00edch \u0111\u01b0\u1ee3c trong c\u00e1c thi\u1ebft k\u1ebf th\u00ed nghi\u1ec7m ki\u1ec3u n\u00e0y l\u00e0 v\u00ec: Th\u1ee9 nh\u1ea5t, do \u1ea3nh h\u01b0\u1edfng c\u1ee7a lu\u1eadn gi\u1ea3i l\u01b0\u1ee1ng t\u00ednh s\u00f3ng h\u1ea1t, coi l\u01b0\u1ee3ng t\u1eed l\u00e0 m\u1ed9t h\u1ea1t c\u01a1 b\u1ea3n kh\u00f4ng th\u1ec3 ph\u00e2n chia \u0111\u01b0\u1ee3c; Th\u1ee9 hai l\u00e0 k\u1ef9 thu\u1eadt th\u0103m d\u00f2 c\u00f2n h\u1ea1n ch\u1ebf trong qu\u00e1 tr\u00ecnh ph\u00e1t tri\u1ec3n c\u00f4ng ngh\u1ec7 th\u0103m d\u00f2 c\u00e1c photon \u0111\u01a1n l\u1ebb, c\u0169ng nh\u01b0 \u0111\u1ed9 nh\u1ea1y v\u00e0 v\u1ea5n \u0111\u1ec1 hi\u1ec7u su\u1ea5t ph\u00e1t hi\u1ec7n c\u1ee7a Avalanche photodiode (APD) \u0111\u1ed1i v\u1edbi \u00e1nh s\u00e1ng ph\u00e2n c\u1ef1c, khi \u0111\u01b0\u1eddng ph\u00e1p tuy\u1ebfn c\u1ee7a m\u1eb7t ph\u1eb3ng ph\u00e2n c\u1ef1c c\u1ee7a photon \u0111\u01a1n l\u1ebb (m\u1eb7t ph\u1eb3ng qu\u1ef9 \u0111\u1ea1o quay) g\u1ea7n nh\u01b0 vu\u00f4ng g\u00f3c v\u1edbi h\u01b0\u1edbng th\u0103m d\u00f2, th\u00ec vi\u1ec7c n\u00e0y t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi vi\u1ec7c th\u0103m d\u00f2 \u00e1nh s\u00e1ng ph\u00e2n c\u1ef1c. C\u0169ng ch\u00ednh v\u00ec nh\u1eefng h\u1ea1n ch\u1ebf c\u1ee7a quan \u0111i\u1ec3m tri\u1ebft h\u1ecdc n\u00e0y m\u00e0 n\u1ee5 c\u01b0\u1eddi \u201cM\u00e8o Cheshire\u201d xu\u1ea5t hi\u1ec7n m\u1ed9t c\u00e1ch ma qu\u00e1i tr\u00ean kh\u00f4ng trung.<\/p>\n
Nh\u00ecn chung, \u0111\u1eb1ng sau nh\u1eefng cu\u1ed9c tranh lu\u1eadn kh\u00e1c nhau trong qu\u00e1 tr\u00ecnh ph\u00e1t tri\u1ec3n c\u1ee7a C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed l\u00e0 s\u1ef1 tranh ch\u1ea5p v\u1ec1 nh\u1eadn th\u1ee9c gi\u1eefa c\u00e1c quan \u0111i\u1ec3m tri\u1ebft h\u1ecdc kh\u00e1c nhau, suy cho c\u00f9ng, vi\u1ec7c kh\u00e1m ph\u00e1 ngu\u1ed3n g\u1ed1c c\u1ee7a v\u1eadt ch\u1ea5t trong v\u0169 tr\u1ee5 kh\u00f4ng th\u1ec3 t\u00e1ch r\u1eddi kh\u1ecfi vi\u1ec7c \u0111\u1ed9t ph\u00e1, si\u00eau vi\u1ec7t trong c\u00e1c quan ni\u1ec7m tri\u1ebft h\u1ecdc v\u00e0 nh\u1eadn th\u1ee9c l\u00fd lu\u1eadn v\u1ec1 c\u00e1c chi\u1ec1u th\u1eddi kh\u00f4ng v\u00e0 ph\u01b0\u01a1ng di\u1ec7n t\u1ea7ng th\u1ee9 nh\u1eadn th\u1ee9c. S\u1ef1 \u0111\u1eafm ch\u00ecm trong \u201cT\u00ednh th\u1ef1c t\u1ea1i\u201d c\u1ee7a ch\u1ee7 ngh\u0129a duy v\u1eadt v\u00e0 \u201ctr\u1ea1ng th\u00e1i ch\u1ed3ng ch\u1eadp\u201d \u1ea3o t\u01b0\u1edfng c\u1ee7a ch\u1ee7 ngh\u0129a duy t\u00e2m \u0111an xen c\u00f9ng nhau, t\u1ea1o ra kh\u00f4ng gian cho nh\u1eefng b\u00f3ng ma. Nh\u01b0ng h\u00ecnh \u1ea3nh n\u1ee5 c\u01b0\u1eddi qu\u1ef7 qu\u00e1i c\u1ee7a \u201cM\u00e8o Cheshire\u201d n\u00e0y kh\u00f4ng ph\u1ea3i l\u00e0 bi\u1ec3u hi\u1ec7n c\u1ee7a m\u1ed9t ph\u00e9p m\u00e0u th\u1ef1c s\u1ef1. S\u1ef1 th\u1eadt v\u1ec1 ngu\u1ed3n g\u1ed1c c\u1ee7a v\u0169 tr\u1ee5 v\u00e0 sinh m\u1ec7nh s\u1ebd \u0111\u01b0\u1ee3c ti\u1ebft l\u1ed9, nh\u01b0ng ch\u1eafc ch\u1eafn s\u1ebd \u0111\u01b0\u1ee3c tri\u1ec3n hi\u1ec7n tr\u01b0\u1edbc nh\u00e2n lo\u1ea1i m\u1ed9t c\u00e1ch quang minh l\u1ed7i l\u1ea1c, \u0111\u01b0\u1eddng \u0111\u01b0\u1eddng ch\u00ednh ch\u00ednh.<\/p>\n
T\u00e1i b\u00fat: B\u1edfi v\u00ec t\u00f4i th\u1ea5y m\u1ed9t s\u1ed1 b\u00e0i vi\u1ebft v\u00e0 video tr\u00ean Internet tr\u00edch d\u1eabn c\u00e1c hi\u1ec7n t\u01b0\u1ee3ng qu\u00e1i d\u1ecb trong c\u00e1c th\u00ed nghi\u1ec7m C\u01a1 h\u1ecdc l\u01b0\u1ee3ng t\u1eed xem l\u00e0 ph\u00e9p l\u1ea1, n\u00ean t\u00f4i vi\u1ebft v\u1ec1 nh\u1eadn th\u1ee9c n\u00e0y t\u1eeb g\u00f3c \u0111\u1ed9 ch\u1ee9ng th\u1ef1c Ph\u00e1p nh\u01b0 m\u1ed9t ph\u1ea7n b\u1ed5 sung cho vi\u1ec7c ch\u1ee9ng th\u1ef1c Ph\u00e1p t\u1ed5ng th\u1ec3.<\/p>\n