Fast and robust production of quantum superposition states by the fractional shortcut to adiabaticity

TL;DR

This paper introduces a fractional shortcut to adiabaticity (f-STA) method for efficiently creating quantum superposition states in three- and four-level systems, demonstrating its advantages over existing techniques through theoretical analysis and simulations.

Contribution

The paper proposes the first application of fractional shortcut to adiabaticity (f-STA) for producing quantum superposition states in multi-level systems, showing improved robustness and efficiency.

Findings

f-STA can produce equal-proportion superposition states effectively

f-STA outperforms f-STIRAP in robustness and efficiency

Spontaneous emission effects are mitigated by f-STA

Abstract

The fractional shortcut to adiabaticity (f-STA) for production of quantum superposition states is proposed firstly via a three-level system with $\Lambda$-type linkage pattern and a four-level system with tripod structure. \textcolor[rgb]{1,0,0}{\sout{The fast, robust and efficient}} \textcolor[rgb]{0,0,1}{\uwave{The fast and robust}} production of the coherent superposition states is studied by comparing the populations for the f-STA and the fractional stimulated Raman adiabatic passage (f-STIRAP). The \textcolor[rgb]{1,0,0}{\sout{superposition}} states with equal proportion can be produced by fixing the controllable parameters of the driving pulses at the final moment of the whole process. The effects of the pulse intensity and the time delay of the pulses on the production process are discussed by monitoring the populations on all of the quantum states. In particular, the spontaneous emission arising from the intermediate state is investigated by the quantum master equation. The result reveals that the f-STA exhibits superior advantages over the f-STIRAP in producing the superposition states.