Stimulated Raman adiabatic passage in a three-level superconducting circuit

TL;DR

This paper demonstrates efficient, robust population transfer in a superconducting transmon qubit using stimulated Raman adiabatic passage, with potential applications in quantum control and computation.

Contribution

It benchmarks the stimulated Raman adiabatic passage process in circuit QED, showing high efficiency and robustness, and introduces a hybrid adiabatic-nonadiabatic gate protocol.

Findings

Achieved over 80% population transfer efficiency.

Demonstrated robustness against control pulse timing errors.

Implemented a reversible Raman protocol and hybrid gate.

Abstract

The adiabatic manipulation of quantum states is a powerful technique that has opened up new directions in quantum engineering, enabling tests of fundamental concepts such as the Berry phase and its nonabelian generalization, the observation of topological transitions, and holds the promise of alternative models of quantum computation. Here we benchmark the stimulated Raman adiabatic passage process for circuit quantum electrodynamics, by using the first three levels of a transmon qubit. We demonstrate a population transfer efficiency above 80% between the ground state and the second excited state using two adiabatic Gaussian-shaped control microwave pulses coupled to the first and second transition. The advantage of this techniques is robustness against errors in the timing of the control pulses. By doing quantum tomography at successive moments during the Raman pulses, we investigate the transfer of the population in time-domain. We also show that this protocol can be reversed by applying a third adiabatic pulse on the first transition. Furthermore, we demonstrate a hybrid adiabatic-nonadiabatic gate using a fast pulse followed by the adiabatic Raman sequence, and we study experimentally the case of a quasi-degenerate intermediate level.