Rapid adiabatic passage without level crossing

TL;DR

This paper introduces a novel adiabatic passage technique in quantum systems that achieves complete population transfer without crossing energy levels, using structured pulses with sign changes in Rabi frequency.

Contribution

It presents a new method for adiabatic population transfer that avoids level crossing by employing structured pulses with specific Rabi frequency sign changes.

Findings

Simulations demonstrate complete population inversion and return.

Geometrical interpretation of Bloch vector motion.

Method differs from conventional chirped pulse techniques.

Abstract

We present a method for achieving complete population transfer in a two-state quantum system via adiabatic time evolution in which, contrary to conventional rapid adiabatic passage produced by chirped pulses, there occurs no crossing of diabatic energy curves: there is no sign change of the detuning. Instead, we use structured pulses, in which, in addition to satisfying conditions for adiabatic evolution, there occurs a sign change of the Rabi frequency when the detuning is zero. We present simulations that offer simple geometrical interpretation of the two-dimensional motion of the Bloch vector for this system, illustrating how both complete population inversion and complete population return occur for different choices of structured pulses.