Quantum control of continuous systems via nonharmonic potential modulation

TL;DR

This paper proposes a theoretical method for controlling a single continuous-variable quantum system in a nonharmonic potential to generate complex states and perform quantum operations, with potential experimental applications.

Contribution

It introduces a novel control scheme using potential modulation to create non-Gaussian states and implement unitaries in continuous-variable systems.

Findings

Demonstrates generation of non-Gaussian states like Fock and GKP states.

Proposes protocols for state discrimination and error correction.

Analyzes robustness against noise in control schemes.

Abstract

We present a theoretical proposal for preparing and manipulating a state of a single continuous-variable degree of freedom confined to a nonharmonic potential. By utilizing optimally controlled modulation of the potential's position and depth, we demonstrate the generation of non-Gaussian states, including Fock, Gottesman-Kitaev-Preskill, multi-legged-cat, and cubic-phase states, as well as the implementation of arbitrary unitaries within a selected two-level subspace. Additionally, we propose protocols for single-shot orthogonal state discrimination, algorithmic cooling, and correcting for nonlinear evolution. We analyze the robustness of this control scheme against noise. Since all the presented protocols rely solely on the precise modulation of the effective nonharmonic potential landscape, they are relevant to several experiments with continuous-variable systems, including the motion of a single particle in an optical tweezer or lattice, or current in circuit quantum electrodynamics.