Single-shot measurement of the Josephson charge qubit

2004/02/25 by O. V. Astafiev, O. Astafiev, Yu. A. Pashkin +6 · 3 citations
Computer Science · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum Information and Cryptography #Quantum and electron transport phenomena #cond-mat.mes-hall #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.69.180507

submitted to Rapid Communications of Phys. Rev. B (february 2004)

arxiv created 2004/02/25 · openalex publication_date 2004/05/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30

Abstract

We demonstrate single-shot readout of quantum states of the Josephson charge qubit. The quantum bits are transformed into and stored as classical bits (charge quanta) in a dynamic memory cell---a superconducting island. The transformation of state |1〉 (differing form state |0〉 by an extra Cooper pair) is a result of a controllable quasiparticle tunneling to the island. The charge is then detected by a conventional single-electron transistor, electrostatically decoupled from the qubit. We study relaxation dynamics in the system and obtain the readout efficiency of 87% and 93% for |1〉 and |0〉 states, respectively.

Citations

• Coherent control of macroscopic quantum states in a single-Cooper-pair box
• Quantum measurements performed with a single-electron transistor
• Coherent Quantum Dynamics of a Superconducting Flux Qubit
• Demonstration of conditional gate operation using superconducting charge qubits
• Full Frequency Back-Action Spectrum of a Single-Electron Transistor during Qubit Readout
• Quantum-state engineering with Josephson-junction devices

Cited by

• Efficient one-step generation of large cluster states with solid-state circuits
• Initial Decoherence in Solid State Qubits
• Potential errors in a scheme of universal quantum gates in Kane’s model