Quantum state control with a superconducting qubit

N. V. Klenov, Igor I. Soloviev, А. В. Кузнецов +3 more

Andrew N. Cleland

There has been tremendous progress in the capabilities of superconducting quantum circuits, both for fundamental quantum science as well as for applications in quantum information. Superconducting qubits are based on the Josephson junction, which provides the fundamental inductive nonlinearity that affords full quantum control of otherwise quite simple electrical circuits. I will outline how a superconducting qubit can be used to measure and control the quantum state of a nanomechanical system [1], completely control multi-photon states in superconducting resonators [2,3], factor the number 15 using a von Neumannstyle computing architecture [4,5], and possibly allow the transfer of a GHz-frequency quantum state to an optical signal.

Yasunobu Nakamura

Irfan A. Siddiqi

Liang Jiang, C. L. Kane, John P. Preskill

We propose and analyze an interface between a topological qubit and a superconducting flux qubit. In our scheme, the interaction between Majorana fermions in a topological insulator is coherently controlled by a superconducting phase that depends on the quantum state of the flux qubit. A controlled-phase gate, achieved by pulsing this interaction on and off, can transfer quantum information between the topological qubit and the superconducting qubit.

Sergey Borisenok