Quantum Control via Stimulated Raman User-defined Passage

TL;DR

This paper introduces STIRUP, a flexible and efficient alternative to STIRAP for quantum state transfer, demonstrating faster operation, higher fidelity, and robustness in superconducting qubits.

Contribution

The paper proposes and experimentally validates STIRUP, a user-defined passage method that improves speed and fidelity over traditional STIRAP in quantum control.

Findings

STIRUP is over four times faster than STIRAP.

Achieved a 99.5% fidelity in state transfer.

STIRUP enhances robustness and can replace STIRAP in many applications.

Abstract

Stimulated Raman adiabatic passage (STIRAP) is a widely-used technique of coherent state-to-state manipulation for many applications in physics, chemistry, and beyond. The adiabatic evolution of the state involved in STIRAP, called adiabatic passage, guarantees its robustness against control errors, but also leads to problems of low efficiency and decoherence. Here we propose and experimentally demonstrate an alternative approach, termed stimulated Raman "user-defined" passage (STIRUP), where a parameterized state is employed for constructing desired evolutions to replace the adiabatic passage in STIRAP. The user-defined passages can be flexibly designed for optimizing different objectives for different tasks, e.g. minimizing leakage error. To experimentally benchmark its performance, we apply STIRUP to the task of coherent state transfer in a superconducting Xmon qutrit. We found that STIRUP completed the transfer more then four times faster than STIRAP with enhanced robustness, and achieved a fidelity of 99.5%, which is the highest among all recent experiments based on STIRAP and its variants. In practice, STIRUP differs from STIRAP only in the design of driving pulses; therefore, most existing applications of STIRAP can be readily implemented with STIRUP.