Semiclassical fast-forward shortcuts to adiabaticity

TL;DR

This paper introduces a new method for quantum shortcuts to adiabaticity that can efficiently steer wavefunctions between eigenstates in finite time, overcoming previous limitations to only the ground state.

Contribution

The authors develop a novel approach that extends semiclassical fast-forward shortcuts to include excited states, broadening the technique's applicability.

Findings

Method successfully applies to excited states beyond the ground state

Numerical simulations demonstrate effectiveness of the approach

Semiclassical analysis provides theoretical insights

Abstract

In fast forward quantum shortcuts to adiabaticity, a designed potential $U_{FF}(q,t)$ steers a wavefunction to evolve from the $n$'th eigenstate of an initial Hamiltonian $\hat H(0)$ to the $n$'th eigenstate of a final Hamiltonian $\hat H(\tau)$, in finite time $\tau$. Previously proposed strategies for constructing $U_{FF}$ are (in the absence of special symmetries) limited to the ground state, $n=0$. We develop a method that overcomes this limitation, thereby substantially expanding the applicability of this shortcut to adiabaticity, and we illustrate its effectiveness with numerical simulations. Semiclassical analysis provides insight and establishes a close correspondence with the analogous classical fast forward method.