Backaction effects of a SSET measuring a qubit spectroscopy and ground State measurement

Author

Turek, Benjamin ; Majer, Johannes ; Clerk, Aashish ; Girvin, Steve ; Wallraff, Andreas ; Bladh, Kevin ; Gunnarsson, David ; Duty, Tim ; Delsing, Per ; Schoelkopf, Robert

Author_Institution

Dept. of Appl. Phys. & Phys., Yale Univ., New Haven, CT, USA

Volume

15

Issue

2

fYear

2005

fDate

6/1/2005 12:00:00 AM

Firstpage

880

Lastpage

883

Abstract

We investigate the backaction of superconducting single-electron transistor (SSET) continuously measuring a Cooper-pair box. Due to the minimized backaction of the SSET, we observe a 2e periodic Coulomb staircase according to the two-level system Hamiltonian of the Cooper-pair box. We demonstrate that we can control the quantum broadening of the ground state in-situ. We perform spectroscopy measurements and demonstrate that we have full control over the Cooper-pair box Hamiltonian. The ability to reduce the backaction is a necessary condition to use the SSET as a quantum state readout for the CPB as a qubit.

Keywords

Cooper pairs; Coulomb blockade; Josephson effect; electric field measurement; magnetic field measurement; quantum computing; single electron transistors; spectroscopy; superconducting logic circuits; superconducting transistors; Cooper-pair box; Coulomb staircase; SSET; backaction effects; ground state measurement; quantum computing; qubit spectroscopy; spectroscopy measurements; superconducting devices; superconducting single-electron transistor; Charge measurement; Current measurement; Performance evaluation; Physics; Quantum computing; Single electron transistors; Spectroscopy; Stationary state; Superconducting device noise; Superconducting devices; Quantum computing; superconducting devices;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2005.850096

Filename

1439779