paper

Energy Relaxation Time between Macroscopic Quantum Levels in a Superconducting Persistent Current Qubit

arXiv:cond-mat/0311289 · doi:10.1103/PhysRevLett.92.117904

Abstract

We measured the intrawell energy relaxation time τ_{d} between macroscopic quantum levels in the double well potential of a Nb persistent-current qubit. Interwell population transitions were generated by irradiating the qubit with microwaves. Zero population in the initial well was then observed due to a multi-level decay process in which the initial population relaxed to the lower energy levels during transitions. The qubit's decoherence time, determined from τ_{d}, is longer than 20 microseconds, holding the promise of building a quantum computer with Nb-based superconducting qubits.

18 pages, 5 figures

Energy Relaxation Time between Macroscopic Quantum Levels in a Superconducting Persistent Current Qubit · wovepaper