Shortcuts to adiabaticity designed via time-rescaling follow the same transitionless route

TL;DR

This paper demonstrates that time-rescaling shortcuts to adiabaticity produce transitionless quantum dynamics similar to counterdiabatic methods, with simpler implementation and increased robustness in specific quantum control tasks.

Contribution

The study shows that time-rescaling methods generate transitionless shortcuts equivalent to counterdiabatic protocols, simplifying implementation and enhancing robustness in quantum control.

Findings

TR-based shortcuts are transitionless and relate to adiabatic protocols via time reparametrization.

TR reveals more robust quantum dynamics against parameter variations than counterdiabatic techniques.

Application to STIRAP demonstrates improved speed and robustness of the control process.

Abstract

Time-rescaling (TR) has been recently proposed as a method to engineer fast processes, also known as shortcuts to adiabaticity (STA), which enables the coherent control of quantum systems beyond the adiabatic regime [B. L. Bernardo, Phys. Rev. Res. 2, 013133 (2020)]. The method provides the Hamiltonians that generate the fast processes without requiring information about the instantaneous eigenstates of a reference protocol, whereas experimental implementations dismiss additional coupling fields when compared with adiabatic protocols. Here, we revisit the technique and show that the obtained fast dynamics are transitionless, similar to the ones designed via the famous counterdiabatic (CD) approach. We also show that the time evolution of the STA found via TR relates to that of the reference adiabatic protocol by a simple reparametrization of time. To illustrate our findings, we studied the problem of speeding up the stimulated Raman adiabatic passage (STIRAP) and found out that TR revealed quantum dynamics more robust to parameter variations than those provided by the CD technique. Our results shed new light on the application of TR in the control of larger quantum systems.