Eur. Phys. J. B 40, 321-326 (2004)
https://doi.org/10.1140/epjb/e2004-00280-0

Engineering quantum decoherence of charge qubit via a nanomechanical resonator

¹ Institute of Theoretical Physics, the Chinese Academy of Science, Beijing, 100080, P.R. China
² Applied Physics Department, Beijing University of Technology, Beijing, 100022, P.R. China

Corresponding authors: ^a ydwang@itp.ac.cn - ^b suncp@itp.ac.cn

Received: 9 March 2004
Revised: 21 May 2004
Published online: 9 September 2004

Abstract

We propose a theoretical scheme to observe the loss of quantum coherence through the coupling of the superconducting charge qubit system to a nanomechanical resonator (NAMR), which has already been successfully fabricated in experiment and is convenient to manipulate. With a similar form to the usual cavity QED system, this qubit-NAMR composite system with engineered coupling exhibits the collapse and revival phenomenon in a progressive decoherence process. Corresponding to the two components of superposition of the two charge eigenstates, the state of the nanomechanical resonator evolves simultaneously towards two distinct quasi-classical states. Therefore the generalized “which way" detection by the NAMR induces the quantum decoherence of the charge qubit.