Quantum non-demolition detection of single microwave photons in a circuit

被引：224

作者：

Johnson, B. R. ^{[1
]}

Reed, M. D. ^{[1
]}

Houck, A. A. ^{[2
]}

Schuster, D. I. ^{[1
]}

Bishop, Lev S. ^{[1
]}

Ginossar, E. ^{[1
]}

Gambetta, J. M. ^{[3
,4
]}

DiCarlo, L. ^{[1
]}

Frunzio, L. ^{[1
]}

Girvin, S. M. ^{[1
]}

Schoelkopf, R. J. ^{[1
]}

机构：

[1] Yale Univ, Dept Phys & Appl Phys, New Haven, CT 06511 USA

[2] Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA

[3] Univ Waterloo, Inst Quantum Comp, Waterloo, ON N2L 3G1, Canada

[4] Univ Waterloo, Dept Phys & Astron, Waterloo, ON N2L 3G1, Canada

来源：

NATURE PHYSICS | 2010年 / 6卷 / 09期

基金：

加拿大自然科学与工程研究理事会;

关键词：

STATES; CAVITY;

D O I：

10.1038/NPHYS1710

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Thorough control of quantum measurement is key to the development of quantum information technologies. Many measurements are destructive, removing more information from the system than they obtain. Quantum non-demolition (QND) measurements allow repeated measurements that give the same eigenvalue(1). They could be used for several quantum information processing tasks such as error correction(2), preparation by measurement(3) and one-way quantum computing(4). Achieving QND measurements of photons is especially challenging because the detector must be completely transparent to the photons while still acquiring information about them(5,6). Recent progress in manipulating microwave photons in superconducting circuits(7-9) has increased demand for a QND detector that operates in the gigahertz frequency range. Here we demonstrate a QND detection scheme that measures the number of photons inside a high-quality-factor microwave cavity on a chip. This scheme maps a photon number, n, onto a qubit state in a single-shot by means of qubit-photon logic gates. We verify the operation of the device for n = O and 1 by analysing the average correlations of repeated measurements, and show that it is 90% QND. It differs from previously reported detectors(5,8-11) because its sensitivity is strongly selective to chosen photon number states. This scheme could be used to monitor the state of a photon-based memory in a quantum computer.

引用

页码：663 / 667

页数：5