Robust quantum state transfer using tunable couplers

Abstract

We analyze the transfer of a quantum state between two resonators connected by a superconducting transmission line. Nearly perfect state-transfer efficiency can be achieved by using adjustable couplers and destructive interference to cancel the back-reflection into the transmission line at the receiving coupler. We show that the transfer protocol is robust to parameter variations affecting the transmission amplitudes of the couplers. We also show that the effects of Gaussian filtering, pulse-shape noise, and multiple reflections on the transfer efficiency are insignificant. However, the transfer protocol is very sensitive to frequency mismatch between the two resonators. Moreover, the tunable coupler we considered produces time-varying frequency detuning caused by the changing coupling. This detuning requires an active frequency compensation with an accuracy better than 90% to yield the transfer efficiency above 99%.

25 pages, 17 figures; published version

References in corpus (8)

• The Quantum Internet
• Surface codes: Towards practical large-scale quantum computation
• An Elementary Quantum Network of Single Atoms in Optical Cavities
• Coplanar Waveguide Resonators for Circuit Quantum Electrodynamics
• Electro-Optic Modulation of Single Photons
• A superconducting qubit with Purcell protection and tunable coupling
• Tunable-Cavity QED with Phase Qubits
• High fidelity transfer of an arbitrary quantum state between harmonic oscillators