Semiclassical fast-forward shortcuts to adiabaticity

Abstract

In fast-forward quantum shortcuts to adiabaticity, a designed potential U_{FF}(q,t) steers a wave function to evolve from the nth eigenstate of an initial Hamiltonian H[over ̂](0) to the nth eigenstate of a final Hamiltonian H[over ̂](τ), in finite time τ. 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 to the analogous classical fast-forward method.