Fizika Nizkikh Temperatur: Volume 43, Number 7 (July 2017), p. 969-977    ( to contents , go back )

Quantum eigenstate tomography with qubit tunneling spectroscopy

Anatoly Yu. Smirnov and Mohammad H. Amin

D-Wave Systems Inc., 3033 Beta Ave., Burnaby BC V5G 4M9, Canada
E-mail: asmirnov@dwavesys.com; amin@dwavesys.com

Received February 1, 2017

Abstract

Measurement of the energy eigenvalues (spectrum) of a multi-qubit system has recently become possible by qubit tunneling spectroscopy (QTS). In the standard QTS experiments, an incoherent probe qubit is strongly coupled to one of the qubits of the system in such a way that its incoherent tunneling rate provides information about the energy eigenvalues of the original (source) system. In this paper, we generalize QTS by coupling the probe qubit to many source qubits. We show that by properly choosing the couplings, one can perform projective measurements of the source system energy eigenstates in an arbitrary basis, thus performing quantum eigenstate tomography. As a practical example of a limited tomography, we apply our scheme to probe the eigenstates of a kink in a frustrated transverse Ising chain.

PACS: 03.67.–a Quantum information;
PACS: 03.67.Lx Quantum computation architectures and implementations;
PACS: 85.25.Am Superconducting device characterization, design, and modeling.

Key words: superconducting quantum devices, qubit tunneling spectroscopy, quantum information.

Published online: May 25, 2017

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ISSN: 0132-6414 (Print) | ISSN: 1816-0328 (Online)