Population transfer under local dephasing

TL;DR

This paper analyzes quantum population transfer between spins under local dephasing noise, providing analytic expressions and demonstrating how stronger coupling or longer duration can mitigate dephasing effects.

Contribution

It derives an analytic expression for transfer efficiency under specific protocols and shows how to suppress dephasing effects in quantum spin transfer.

Findings

Dephasing reduces transfer efficiency.

Stronger laser coupling improves robustness.

Longer laser duration mitigates dephasing effects.

Abstract

Stimulated Raman adiabatic passage is a well-known technique for quantum population transfer due to its robustness again various sources of noises. Here we consider quantum population transfer from one spin to another via an intermediate spin which subjects to dephasing noise. We obtain an analytic expression for the transfer efficiency under a specific driving protocol, showing that dephasing could reduce the transfer efficiency, but the effect of dephasing could also be suppressed with a stronger laser coupling or a longer laser duration. We also consider another commonly used driving protocol, which shows that this analytic picture is still qualitatively correct.