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
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.
PACS: 03.65.-w – Quantum mechanics / 74.50.+r – Tunneling phenomena; point contacts, weak links, Josephson effects / 03.67.Lx – Quantum computation / 85.25.Dq – Superconducting quantum interference devices (SQUIDs)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004