Ultra-short strong excitation of two-level systems

TL;DR

This paper models how ultra-short, strong, phase-modulated pulses can precisely control the excited state population in two-level quantum systems, advancing quantum control techniques.

Contribution

It introduces a novel model for off-resonance excitation using finite-time phase jumps in ultra-short pulses for quantum state control.

Findings

Numerical solutions show effective population control via phase transient shaping.

Phase jumps over finite time intervals influence excitation efficiency.

The method enables precise manipulation of two-level system populations.

Abstract

We present a model describing the use of ultra-short strong pulses to control the population of the excited level of a two-level quantum system. In particular, we study an off-resonance excitation with a few cycles pulse which presents a smooth phase jump i.e. a change of the pulse's phase which is not step-like, but happens over a finite time interval. A numerical solution is given for the time-dependent probability amplitude of the excited level. The control of the excited level's population is obtained acting on the shape of the phase transient, and other parameters of the excitation pulse.