Measurement efficiency and n-shot readout of spin qubits -: art. no. 106804

被引：51

作者：

Engel, HA

Golovach, VN

Loss, D

Vandersypen, LMK

Elzerman, JM

Hanson, R

Kouwenhoven, LP

机构：

[1] Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland

[2] Dept Nanosci, NL-2600 GA Delft, Netherlands

[3] ERATO Mesoscop Correlat Project, NL-2600 GA Delft, Netherlands

来源：

PHYSICAL REVIEW LETTERS | 2004年 / 93卷 / 10期

关键词：

D O I：

10.1103/PhysRevLett.93.106804

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We consider electron spin qubits in quantum dots and define a measurement efficiency e to characterize reliable measurements via n-shot readouts. We propose various implementations based on a double dot and a quantum point contact (QPC) and show that the associated efficiencies e vary between 50% and 100%, allowing single-shot readout in the latter case. We model the readout microscopically and derive its time dynamics in terms of a generalized master equation, calculate the QPC current, and show that it allows spin readout under realistic conditions.

引用

收藏

页码：106804 / 1

页数：4

相关论文

共 25 条

[11] Continuous quantum measurement of two coupled quantum dots using a point contact: A quantum trajectory approach [J].

Goan, HS ;

Milburn, GJ ;

Wiseman, HM ;

Sun, HB .

PHYSICAL REVIEW B, 2001, 63 (12)

[12] Ultrafast manipulation of electron spin coherence [J].

Gupta, JA ;

Knobel, R ;

Samarth, N ;

Awschalom, DD .

SCIENCE, 2001, 292 (5526) :2458-2461

[13] Measurements with a noninvasive detector and dephasing mechanism [J].

Gurvitz, SA .

PHYSICAL REVIEW B, 1997, 56 (23) :15215-15223

[14] Zeeman energy and spin relaxation in a one-electron quantum dot [J].

Hanson, R ;

Witkamp, B ;

Vandersypen, LMK ;

van Beveren, LHW ;

Elzerman, JM ;

Kouwenhoven, LP .

PHYSICAL REVIEW LETTERS, 2003, 91 (19)

[15] Coherent manipulation of electronic states in a double quantum dot [J].

Hayashi, T ;

Fujisawa, T ;

Cheong, HD ;

Jeong, YH ;

Hirayama, Y .

PHYSICAL REVIEW LETTERS, 2003, 91 (22)

[16] Single-spin measurement using single-electron transistors to probe two-electron systems [J].

Kane, BE ;

McAlpine, NS ;

Dzurak, AS ;

Clark, RG ;

Milburn, GJ ;

Sun, HB ;

Wiseman, H .

PHYSICAL REVIEW B, 2000, 61 (04) :2961-2972

[17] Selective quantum evolution of a qubit state due to continuous measurement [J].

Korotkov, AN .

PHYSICAL REVIEW B, 2001, 63 (11)

[18] Quantum computation with quantum dots [J].

Loss, D ;

DiVincenzo, DP .

PHYSICAL REVIEW A, 1998, 57 (01) :120-126

[19] Real-time detection of electron tunnelling in a quantum dot [J].

Lu, W ;

Ji, ZQ ;

Pfeiffer, L ;

West, KW ;

Rimberg, AJ .

NATURE, 2003, 423 (6938) :422-425

[20] Statistics and noise in a quantum measurement process [J].

Makhlin, Y ;

Schön, G ;

Shnirman, A .

PHYSICAL REVIEW LETTERS, 2000, 85 (21) :4578-4581