摘要We study the time evolution of two electron spin states in a double quantum-dot system, which includes a nearby quantum point contact (QPC) as a measurement device. We find that the QPC measurement induced decoherence is in the micrsecond timescale. We also find that the enhanced QPC measurement will trap the system in its initial spin states, which is consistent with the quantum Zeno effect.
Abstract:We study the time evolution of two electron spin states in a double quantum-dot system, which includes a nearby quantum point contact (QPC) as a measurement device. We find that the QPC measurement induced decoherence is in the micrsecond timescale. We also find that the enhanced QPC measurement will trap the system in its initial spin states, which is consistent with the quantum Zeno effect.
(Foundations of quantum mechanics; measurement theory)
引用本文:
ZHU Fei-Yun;TU Tao;HAO Xiao-Jie;GUO Guang-Can;GUO Guo-Ping. Effect of Quantum Point Contact Measurement on Electron Spin State in Quantum Dots[J]. 中国物理快报, 2009, 26(5): 50301-050301.
ZHU Fei-Yun, TU Tao, HAO Xiao-Jie, GUO Guang-Can, GUO Guo-Ping. Effect of Quantum Point Contact Measurement on Electron Spin State in Quantum Dots. Chin. Phys. Lett., 2009, 26(5): 50301-050301.
[1] Loss D and DiVincenzo D P 1998 Phys. Rev. A 57120 [2] Hanson R, Kouwenhoven L P, Petta J R, Tarucha S andVandersypen L M K 2007 Rev. Mod. Phys. 79 1217 [3] Taylor J M, Engel H A, Dur W, Yacoby A, Marcus C M, ZollerP and Lukin M D 2005 Nature Phys. 1 177 [4] Khaetskii A V and Nazarov Y V 2000 Phys. Rev. B 61 12639 [5] Khaetskii A V and Nazarov Y V 2001 Phys. Rev. B 64 125316 [6] Golovach V N, Khaetskii A V and Loss D 2004 Phys.Rev. Lett. 93 016601 [7] Khaetskii A V, Loss D and Glazman L 2002 Phys. Rev.Lett. 93 186602 [8] Taylor J M, Petta J R, Johnson A C, Yacoby A, Marcus C Mand Lukin M D 2007 Phys. Rev. B 76 035315 [9] Elzerman J M, Hanson R, Willems van Beveren L H, WitkampB, Vandersypen L M K and Kouwenhoven L P 2004 Nature 430431 [10] Petta J R, Johnson A C, Taylor J M, Laird E A, Yacoby A,Lukin M D, Marcus C M, Hanson M P and Gossard A C 2005 Science 309 2180 [11] Reilly D J, Taylor J M, Petta J R, Marcus C M, Hanson M Pand Gossard A C 2008 Science 321 817 [12] Gurvitz S A 1997 Phys. Rev. B 56 15215 [13] Engel H A, Golovach V N, Loss D, Vandersypen L M K,Elzerman J M, Hanson R and Kouwenhoven L P 2004 Phys. Rev.Lett. 93 106804 [14] Shaji N, Simmons C B, Thalakulam M et al 2008 NaturePhysics 4 540 [15] Trauzettel B, Bulaev D V, Loss D and Burkard G 2007 Nature Phys. 3 192 [16] Blum K 1996 Density Matrix Theory and Applications(New York: Plenum) chap 8