{"id":5932,"date":"2017-06-14T18:53:43","date_gmt":"2017-06-14T11:53:43","guid":{"rendered":"http:\/\/ttud.com.vn\/?p=5932"},"modified":"2017-10-03T11:03:01","modified_gmt":"2017-10-03T04:03:01","slug":"tim-ra-duoc-tu-tinh-ben-trong-vat-lieu-2d","status":"publish","type":"post","link":"https:\/\/casta.ttud.com.vn\/index.php\/tim-ra-duoc-tu-tinh-ben-trong-vat-lieu-2d\/","title":{"rendered":"T\u00ecm ra \u0111\u01b0\u1ee3c t\u1eeb t\u00ednh b\u00ean trong v\u1eadt li\u1ec7u 2D"},"content":{"rendered":"

M\u1edbi \u0111\u00e2y, nh\u00f3m nghi\u00ean c\u1ee9u c\u1ee7a Tr\u01b0\u1eddng \u0110\u1ea1i h\u1ecdc Washington v\u00e0 Vi\u1ec7n C\u00f4ng ngh\u1ec7 Massachusetts \u0111\u00e3 l\u1ea7n \u0111\u1ea7u ti\u00ean ph\u00e1t hi\u1ec7n ra t\u1eeb t\u00ednh trong th\u1ebf gi\u1edbi 2D c\u1ee7a c\u00e1c v\u1eadt li\u1ec7u \u0111\u01b0\u1ee3c t\u1ea1o ra t\u1eeb c\u00e1c l\u1edbp nguy\u00ean t\u1eed \u0111\u01a1n v\u00e0 monolayer (\u0111\u01a1n l\u1edbp)<\/strong><\/p>\n

\"\"<\/p>\n

V\u1eadt li\u1ec7u c\u00f3 t\u1eeb t\u00ednh (nam ch\u00e2m) t\u1ea1o n\u00ean n\u1ec1n t\u1ea3ng c\u00e1c c\u00f4ng ngh\u1ec7 nh\u01b0 c\u00e1c thi\u1ebft b\u1ecb l\u01b0u tr\u1eef d\u1eef li\u1ec7u \u1ed5 c\u1ee9ng v\u00e0 c\u1ea3m bi\u1ebfn \u0111\u00f3ng vai tr\u00f2 ng\u00e0y c\u00e0ng quan tr\u1ecdng trong cu\u1ed9c s\u1ed1ng c\u1ee7a ch\u00fang ta ng\u00e0y nay.<\/p>\n

Nh\u01b0ng khi ch\u00fang ta mong mu\u1ed1n c\u00f3 \u0111\u01b0\u1ee3c c\u00e1c thi\u1ebft b\u1ecb nh\u1ecf h\u01a1n v\u00e0 nhanh h\u01a1n th\u00ec \u0111\u00f2i h\u1ecfi c\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u ph\u1ea3i t\u00ecm ra \u0111\u01b0\u1ee3c c\u00e1c lo\u1ea1i v\u1eadt li\u1ec7u c\u00f3 t\u1eeb t\u00ednh m\u1edbi, nh\u1ecf g\u1ecdn h\u01a1n, hi\u1ec7u qu\u1ea3 h\u01a1n v\u00e0 c\u00f3 th\u1ec3 ki\u1ec3m so\u00e1t \u0111\u01b0\u1ee3c b\u1eb1ng c\u00e1c ph\u01b0\u01a1ng ph\u00e1p \u1ee9ng d\u1ee5ng ch\u00ednh x\u00e1c v\u00e0 \u0111\u00e1ng tin c\u1eady.<\/p>\n

M\u1edbi \u0111\u00e2y, nh\u00f3m nghi\u00ean c\u1ee9u c\u1ee7a Tr\u01b0\u1eddng \u0110\u1ea1i h\u1ecdc Washington v\u00e0 Vi\u1ec7n C\u00f4ng ngh\u1ec7 Massachusetts \u0111\u00e3 l\u1ea7n \u0111\u1ea7u ti\u00ean ph\u00e1t hi\u1ec7n ra t\u1eeb t\u00ednh trong th\u1ebf gi\u1edbi 2D c\u1ee7a c\u00e1c v\u1eadt li\u1ec7u \u0111\u01b0\u1ee3c t\u1ea1o ra t\u1eeb c\u00e1c l\u1edbp nguy\u00ean t\u1eed \u0111\u01a1n v\u00e0 monolayer (\u0111\u01a1n l\u1edbp). C\u00f4ng tr\u00ecnh n\u00e0y \u0111\u00e3 \u0111\u01b0\u1ee3c c\u00f4ng b\u1ed1 tr\u00ean t\u1ea1p ch\u00ed Nature cho th\u1ea5y c\u00e1c \u0111\u1eb7c t\u00ednh t\u1eeb t\u00ednh c\u00f3 th\u1ec3 t\u1ed3n t\u1ea1i th\u1eadm ch\u00ed \u1edf c\u1ea3 trong l\u0129nh v\u1ef1c 2D – m\u1edf ra m\u1ed9t th\u1ebf gi\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng ti\u1ec1m n\u0103ng m\u1edbi.<\/p>\n

\u201c\u0110i\u1ec1u m\u00e0 ch\u00fang t\u00f4i t\u00ecm th\u1ea5y \u1edf \u0111\u00e2y l\u00e0 v\u1eadt li\u1ec7u 2D c\u00e1ch nhi\u1ec7t c\u00f3 t\u1eeb t\u00ednh \u1edf b\u00ean trong, v\u00e0 t\u1eeb t\u00ednh trong c\u1ea5u tr\u00fac n\u00e0y ho\u1ea1t \u0111\u1ed9ng r\u1ea5t m\u1ea1nh. Ch\u00fang t\u00f4i cho r\u1eb1ng nh\u1eefng c\u00f4ng ngh\u1ec7 th\u00f4ng tin m\u1edbi c\u00f3 th\u1ec3 ph\u00e1t tri\u1ec3n d\u1ef1a tr\u00ean nh\u1eefng nam ch\u00e2m 2-D m\u1edbi n\u00e0y\u201d, Xiaodong Xu, gi\u00e1o s\u01b0 v\u1eadt l\u00fd h\u1ecdc v\u00e0 v\u1eadt li\u1ec7u khoa h\u1ecdc v\u00e0 k\u1ef9 thu\u1eadt c\u1ee7a UW, v\u00e0 l\u00e0 th\u00e0nh vi\u00ean c\u1ee7a Vi\u1ec7n N\u0103ng l\u01b0\u1ee3ng s\u1ea1ch UW n\u00f3i.<\/p>\n

Xu v\u00e0 gi\u00e1o s\u01b0 v\u1eadt l\u00fd Pablo Jarillo-Herrero t\u1ea1i MIT \u0111\u1ee9ng \u0111\u1ea7u nh\u00f3m c\u00e1c nh\u00e0 khoa h\u1ecdc qu\u1ed1c t\u1ebf \u0111\u00e3 ch\u1ee9ng minh \u0111\u01b0\u1ee3c r\u1eb1ng v\u1eadt li\u1ec7u n\u00e0y – chromium triiodide (CrI3) – c\u00f3 c\u00e1c \u0111\u1eb7c t\u00ednh t\u1eeb t\u00ednh b\u00ean trong c\u1ea5u t\u1ea1o \u0111\u01a1n l\u1edbp c\u1ee7a ch\u00ednh n\u00f3.<\/p>\n

C\u00e1c nh\u00f3m nghi\u00ean c\u1ee9u kh\u00e1c, bao g\u1ed3m Michael McGuire, l\u00e0m vi\u1ec7c t\u1ea1i ph\u00f2ng th\u00ed nghi\u1ec7m Qu\u1ed1c gia Oak Ridge, v\u00e0 l\u00e0 \u0111\u1ed3ng t\u00e1c gi\u1ea3 nghi\u00ean c\u1ee9u, tr\u01b0\u1edbc \u0111\u00e2y \u0111\u00e3 ch\u1ec9 ra r\u1eb1ng CrI3 – b\u00ean trong c\u1ea5u tr\u00fac tinh th\u1ec3 l\u1edbn, 3D, \u0111a l\u1edbp – l\u00e0 s\u1eaft t\u1eeb. B\u00ean trong c\u00e1c v\u1eadt li\u1ec7u s\u1eaft t\u1eeb, c\u00e1c \u201cspin\u201d c\u1ee7a c\u00e1c ph\u00e2n t\u1eed electron, t\u01b0\u01a1ng t\u1ef1 nh\u01b0 c\u00e1c c\u1ee5c nam ch\u00e2m h\u1ea1 nguy\u00ean t\u1eed, nh\u1ecf x\u00edu, c\u00f3 tr\u1eadt t\u1ef1 t\u1eeb \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp theo m\u1ed9t h\u01b0\u1edbng gi\u1ed1ng nhau, th\u1eadm ch\u00ed c\u00f2n kh\u00f4ng c\u00f3 t\u1eeb tr\u01b0\u1eddng b\u00ean ngo\u00e0i. Trong th\u1ef1c t\u1ebf, c\u00e1c v\u1eadt li\u1ec7u \u0111\u01a1n l\u1edbp n\u00e0y c\u00f3 th\u1ec3 b\u1ed9c l\u1ed9 cho th\u1ea5y c\u00e1c \u0111\u1eb7c t\u00ednh t\u00ednh ch\u1ea5t \u0111\u1ed9c \u0111\u00e1o m\u00e0 kh\u00f4ng c\u1ea7n ph\u1ea3i quan s\u00e1t b\u00ean trong trong c\u1ea5u tr\u00fac 3-D \u0111a l\u1edbp c\u1ee7a ch\u00fang.<\/p>\n

Theo Bevin Huang, nghi\u00ean c\u1ee9u sinh t\u1ea1i UW, v\u00e0 l\u00e0 \u0111\u1ed3ng t\u00e1c gi\u1ea3 nghi\u00ean c\u1ee9u cho bi\u1ebft: \u201cKh\u00f4ng th\u1ec3 d\u1ef1 \u0111o\u00e1n tr\u01b0\u1edbc m\u1ed9t c\u00e1ch ch\u00ednh x\u00e1c c\u00e1c \u0111\u1eb7c t\u00ednh h\u00f3a h\u1ecdc hay v\u1eadt l\u00fd, t\u1eeb t\u00ednh v\u00e0 \u0111i\u1ec7n n\u0103ng c\u1ee7a c\u00e1c tinh th\u1ec3 2D \u0111\u01a1n l\u1edbp d\u1ef1a v\u00e0o h\u00e0nh vi c\u1ee7a b\u1ea3n sao 3D c\u1ee1 l\u1edbn c\u1ee7a n\u00f3\u201d.<\/p>\n

C\u00e1c nguy\u00ean t\u1eed b\u00ean trong c\u00e1c v\u1eadt li\u1ec7u \u0111\u01a1n l\u1edbp \u0111\u01b0\u1ee3c xem l\u00e0 \u201cc\u00f3 ch\u1ee9c n\u0103ng\u201d hai chi\u1ec1u (2D) b\u1edfi v\u00ec c\u00e1c electron ch\u1ec9 c\u00f3 th\u1ec3 di chuy\u1ec3n b\u00ean trong t\u1ea5m nguy\u00ean t\u1eed n\u00e0y, gi\u1ed1ng nh\u01b0 c\u00e1c qu\u00e2n c\u1edd ch\u1ec9 di chuy\u1ec3n \u0111\u01b0\u1ee3c trong b\u00e0n c\u1edd.<\/p>\n

\u0110\u1ec3 kh\u00e1m ph\u00e1 c\u00e1c \u0111\u1eb7c t\u00ednh c\u1ee7a CrI3 \u1edf d\u1ea1ng 2D, nh\u00f3m \u0111\u00e3 s\u1eed d\u1ee5ng b\u0103ng keo trong su\u1ed1t Scotch \u0111\u1ec3 b\u00e0o l\u1ea5y m\u1ed9t l\u1edbp \u0111\u01a1n c\u1ee7a CrI3 b\u00ean trong tinh th\u1ec3 c\u1ea5u tr\u00fac 3D x\u1ebfp ch\u1ed3ng.<\/p>\n

\u201cHi\u1ec7u qu\u1ea3 c\u1ee7a vi\u1ec7c s\u1eed d\u1ee5ng b\u0103ng keo trong su\u1ed1t Scotch \u0111\u1ec3 b\u00f3c t\u00e1ch m\u1ed9t l\u1edbp \u0111\u01a1n ra kh\u1ecfi tinh th\u1ec3 3D c\u00f3 c\u1ea5u tr\u00fac x\u1ebfp ch\u1ed3ng th\u1eadt \u0111\u00e1ng ng\u1ea1c nhi\u00ean. K\u1ef9 thu\u1eadt gi\u00e1 r\u1ebb v\u00e0 \u0111\u01a1n gi\u1ea3n n\u00e0y l\u1ea7n \u0111\u1ea7u ti\u00ean \u0111\u01b0\u1ee3c \u0111\u00e3 s\u1eed d\u1ee5ng t\u00e1ch graphene ra kh\u1ecfi graphite c\u00f3 c\u1ea5u tr\u00fac 2D, v\u00e0 sau \u0111\u00f3 c\u0169ng \u0111\u00e3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng th\u00e0nh c\u00f4ng v\u1edbi c\u00e1c v\u1eadt li\u1ec7u kh\u00e1c\u201d. Genevieve Clark n\u00f3i.<\/p>\n

B\u00ean trong c\u00e1c v\u1eadt li\u1ec7u s\u1eaft t\u1eeb, c\u00e1c spin c\u00e1c electron c\u00f3 tr\u1eadt t\u1ef1 th\u1eb3ng h\u00e0ng n\u00e0y s\u1ebd t\u1ea1o ra c\u00e1c d\u1ea5u hi\u1ec7u b\u00e1o hi\u1ec7u khi m\u1ed9t ch\u00f9m \u00e1nh s\u00e1ng ph\u00e2n c\u1ef1c ph\u1ea3n chi\u1ebfu b\u1ec1 m\u1eb7t c\u1ee7a v\u1eadt li\u1ec7u n\u00e0y. C\u00e1c nh\u00e0 nghi\u00ean c\u1ee9u s\u1ebd ph\u00e1t hi\u1ec7n ra d\u1ea5u hi\u1ec7u n\u00e0y trong CrI3 nh\u1edd v\u00e0o vi\u1ec7c s\u1eed d\u1ee5ng m\u1ed9t lo\u1ea1i k\u00ednh hi\u1ec3n vi \u0111\u1eb7c bi\u1ec7t.<\/p>\n

\u0110\u00e1ng ng\u1ea1c nhi\u00ean l\u00e0 trong c\u00e1c l\u1edbp CrI3 c\u00f3 \u0111\u1ed9 d\u00e0y 2 l\u1edbp, d\u1ea5u hi\u1ec7u quang h\u1ecdc kh\u00f4ng xu\u1ea5t hi\u1ec7n. \u0110i\u1ec1u n\u00e0y cho th\u1ea5y r\u1eb1ng c\u00f3 m\u1ed9t s\u1ed1 spin electron \u0111\u00e3 b\u1ecb s\u1eafp x\u1ebfp theo chi\u1ec1u h\u01b0\u1edbng \u0111\u1ed1i ngh\u1ecbch v\u1edbi spin electron kh\u00e1c, v\u00e0 thu\u1eadt ng\u1eef n\u00e0y \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 tr\u1eadt t\u1ef1 ch\u1ed1ng s\u1eaft t\u1eeb.<\/p>\n

T\u00ednh s\u1eaft t\u1eeb quay ng\u01b0\u1ee3c tr\u1edf l\u1ea1i b\u00ean trong CrI3 tam l\u1edbp. \u0110i\u1ec1u n\u00e0y khi\u1ebfn c\u00e1c nh\u00e0 khoa h\u1ecdc s\u1ebd c\u1ea7n ph\u1ea3i ti\u1ebfn h\u00e0nh c\u00e1c nghi\u00ean c\u1ee9u s\u00e2u h\u01a1n \u0111\u1ec3 c\u00f3 th\u1ec3 hi\u1ec3u t\u1ea1i sao CrI3 l\u1ea1i b\u1ed9c l\u1ed9 c\u00e1c pha t\u1eeb t\u00ednh l\u1ec7 thu\u1ed9c t\u1eebng l\u1edbp r\u1ea5t \u0111\u1eb7c bi\u1ec7t n\u00e0y. V\u1edbi Xiaodong Xu, \u0111\u00e2y ch\u1ec9 l\u00e0 m\u1ed9t v\u00e0i \u0111\u1eb7c t\u00ednh \u0111\u1ed9c \u0111\u00e1o \u0111\u01b0\u1ee3c kh\u00e1m hi\u1ec7n th\u1ea5y khi c\u00e1c l\u1edbp \u0111\u01a1n \u0111\u01b0\u1ee3c gh\u00e9p l\u1ea1i.<\/p>\n

Ph\u1ea7n l\u1edbn nghi\u00ean c\u1ee9u c\u1ee7a Gi\u00e1o s\u01b0 Xu xoay quanh v\u00e0o vi\u1ec7c t\u1ea1o ra heterostructure (c\u00f3 c\u1ea5u tr\u00fac kh\u00e1c th\u01b0\u1eddng), c\u1ea5u tr\u00fac n\u00e0y ch\u1ee9a nhi\u1ec1u h\u01a1n 2 lo\u1ea1i v\u1eadt li\u1ec7u si\u00eau m\u1ecfng kh\u00e1c nhau. T\u1ea1i b\u1ec1 m\u1eb7t ph\u00e2n gi\u1edbi gi\u1eefa hai v\u1eadt li\u1ec7u, nh\u00f3m nghi\u00ean c\u1ee9u c\u1ee7a \u00f4ng s\u1ebd c\u1ed1 g\u1eafng t\u00ecm ra c\u00e1c hi\u1ec7n t\u01b0\u1edfng v\u1eadt l\u00fd ho\u1eb7c c\u00e1c ch\u1ee9c n\u0103ng m\u1edbi \u0111\u1ec3 ph\u00e1t tri\u1ec3n c\u00e1c \u1ee9ng d\u1ee5ng ti\u1ec1m n\u0103ng trong c\u00f4ng ngh\u1ec7 m\u00e1y t\u00ednh v\u00e0 c\u00f4ng ngh\u1ec7 th\u00f4ng tin.<\/p>\n

Trong nghi\u00ean c\u1ee9u tr\u01b0\u1edbc \u0111\u01b0\u1ee3c \u0111\u0103ng t\u1ea3i th\u00e1ng tr\u01b0\u1edbc tr\u00ean t\u1ea1p ch\u00ed Science Advances, nh\u00f3m nghi\u00ean c\u1ee9u c\u1ee7a Xu do gi\u00e1o s\u01b0 v\u1eadt l\u00fd v\u00e0 k\u1ef9 thu\u1eadt \u0111i\u1ec7n Kai-Mei Fu \u0111\u1ee9ng \u0111\u1ea7u \u0111\u00e3 cho th\u1ea5y c\u1ea5u tr\u00fac si\u00eau m\u1ecfng c\u1ee7a CrI3 khi x\u1ebfp ch\u1ed3ng l\u00ean nhau m\u1ed9t l\u1edbp vonfram diselenide \u0111\u01a1n l\u1edbp s\u1ebd t\u1ea1o ra m\u1ed9t b\u1ec1 m\u1eb7t c\u00f3 c\u1ea5u tr\u00fac hetero si\u00eau \u0111\u1eb9p v\u1edbi c\u00e1c \u0111\u1eb7c t\u00ednh t\u1eeb t\u00ednh v\u00e0 photonic \u0111\u1ed9c \u0111\u00e1o v\u00e0 r\u1ea5t b\u1ea5t ng\u1edd.<\/p>\n

\u201cNh\u01b0 v\u1eady, c\u1ea5u tr\u00fac Heterostructures n\u1eafm gi\u1eefa c\u00e1c ti\u1ec1m n\u0103ng \u0111\u1ea7y h\u1ee9a h\u1eb9n trong vi\u1ec7c t\u1ea1o ra c\u00e1c \u1ee9ng d\u1ee5ng cho m\u00e1y t\u00ednh, l\u01b0u tr\u1eef d\u1eef li\u1ec7u, th\u00f4ng tin li\u00ean l\u1ea1c v\u00e0 c\u00e1c \u1ee9ng d\u1ee5ng kh\u00e1c m\u00e0 ch\u00fang ta ch\u01b0a bi\u1ebft \u0111\u1ebfn\u201d, Xu cho bi\u1ebft.<\/p>\n

P.T.T-NASATI (Theo Phys)<\/em><\/p>\n

Ngu\u1ed3n D\u00e2n Tr\u00ed<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

M\u1edbi \u0111\u00e2y, nh\u00f3m nghi\u00ean c\u1ee9u c\u1ee7a Tr\u01b0\u1eddng \u0110\u1ea1i h\u1ecdc Washington v\u00e0 Vi\u1ec7n C\u00f4ng ngh\u1ec7 Massachusetts \u0111\u00e3 l\u1ea7n \u0111\u1ea7u ti\u00ean ph\u00e1t hi\u1ec7n ra t\u1eeb t\u00ednh trong th\u1ebf gi\u1edbi 2D c\u1ee7a c\u00e1c v\u1eadt li\u1ec7u \u0111\u01b0\u1ee3c t\u1ea1o ra t\u1eeb c\u00e1c l\u1edbp nguy\u00ean t\u1eed \u0111\u01a1n v\u00e0 monolayer (\u0111\u01a1n l\u1edbp) V\u1eadt li\u1ec7u c\u00f3 t\u1eeb t\u00ednh (nam ch\u00e2m) t\u1ea1o n\u00ean n\u1ec1n […]<\/p>\n","protected":false},"author":17,"featured_media":6527,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[],"class_list":["post-5932","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tin-tuc"],"_links":{"self":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/5932","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/users\/17"}],"replies":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/comments?post=5932"}],"version-history":[{"count":2,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/5932\/revisions"}],"predecessor-version":[{"id":6528,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/5932\/revisions\/6528"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/media\/6527"}],"wp:attachment":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/media?parent=5932"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/categories?post=5932"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/tags?post=5932"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}