High-fidelity gates in a single josephson qubit.
We demonstrate new experimental procedures for measuring small errors in a superconducting quantum bit (qubit). By carefully separating out gate and measurement errors, we construct a complete error budget and demonstrate single qubit gate fidelities of 0.98, limited by energy relaxation. We also introduce a new metrology tool-- Ramsey interference error filter-that can measure the occupation probability of the state |2> which is outside the computational basis, down to 10{-4}, thereby confirming that our quantum system stays within the qubit manifold during single qubit logic operations.
Lucero
Erik
E
Department of Physics, University of California at Santa Barbara, Broida Hall, Santa Barbara, California 93106, USA.
Hofheinz
M
M
Ansmann
M
M
Bialczak
Radoslaw C
RC
Katz
N
N
Neeley
Matthew
M
O'Connell
A D
AD
Wang
H
H
Cleland
A N
AN
Martinis
John M
JM