Characterization of a qubit Hamiltonian using adaptive measurements in a fixed basis

被引:71
作者
Sergeevich, Alexandr [1 ]
Chandran, Anushya [2 ,3 ,4 ]
Combes, Joshua [2 ,3 ,5 ]
Bartlett, Stephen D. [1 ]
Wiseman, Howard M. [2 ,3 ]
机构
[1] Univ Sydney, Sch Phys, Ctr Engn Quantum Syst, Sydney, NSW 2006, Australia
[2] Griffith Univ, ARC Ctr Quantum Computat & Commun Technol, Brisbane, Qld 4111, Australia
[3] Griffith Univ, Ctr Quantum Dynam, Brisbane, Qld 4111, Australia
[4] Princeton Univ, Dept Phys, Princeton, NJ 08544 USA
[5] Univ New Mexico, Ctr Quantum Informat & Control, Albuquerque, NM 87131 USA
来源
PHYSICAL REVIEW A | 2011年 / 84卷 / 05期
基金
澳大利亚研究理事会; 美国国家科学基金会;
关键词
D O I
10.1103/PhysRevA.84.052315
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
We investigate schemes for Hamiltonian parameter estimation of a two-level system using repeated measurements in a fixed basis. The simplest (Fourier based) schemes yield an estimate with a mean-square error (MSE) that decreases at best as a power law similar to N-2 in the number of measurements N. By contrast, we present numerical simulations indicating that an adaptive Bayesian algorithm, where the time between measurements can be adjusted based on prior measurement results, yields a MSE which appears to scale close to exp(-0.3N). That is, measurements in a single fixed basis are sufficient to achieve exponential scaling in N.
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页数:5
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