Conceptual Problems in Quantum Squeezing

TL;DR

This paper investigates the dynamical operations for quantum squeezing using external fields, providing exactly solvable models and a new approach via Toeplitz matrices to better understand state evolution.

Contribution

It introduces exactly solvable models of quantum squeezing through external fields and applies Toeplitz matrices for a simplified analysis of the evolution operators.

Findings

Explicit solutions for symmetric evolution intervals

Determination of external fields for desired squeezing

Application of Toeplitz matrices simplifies analysis

Abstract

In studies of quantum squeezing, the emphasis is typically placed more on specific squeezed states and their evolution rather than on the dynamical operations that could simultaneously squeeze a broader range of quantum states, regardless of their initial configuration. We explore new developments in this area, facilitated by gently acting external fields which might induce squeezing of the canonical observables $q$ and $p$ in charged particles. The extensive research in this field has yielded many valuable insights, raising the question of whether there is still room for significant new contributions to our understanding. Nonetheless, we present some exactly solvable instances of this problem, observed in symmetric evolution intervals. These intervals allow for the explicit determination of the temporal dependence of external fields necessary to generate the required evolution operators. Our findings are linked with a straightforward application of Toeplitz matrices, offering a more accessible description of the problem compared to the frequently employed Ermakov-Milne invariants.