All You Need is Amplifier: Spectral Imposters Without Pulse Shaping

TL;DR

This paper introduces a real-time feedback control framework for quantum systems that adaptively corrects control fields based on system responses, enabling programmable quantum dynamics without pre-designed waveforms.

Contribution

It presents a novel adaptive feedback control method for quantum systems, moving away from predesigned pulses towards real-time response-based control.

Findings

Successfully mimics argon's optical emission with hydrogen

Reproduces Mott-insulating transport dynamics in a Fermi-Hubbard chain

Demonstrates broad applicability of closed-loop quantum control

Abstract

Quantum tracking control encodes the desired dynamics into a tailored driving field; here, we let the system find its own way there. We propose a real-time feedback control framework in which a proportional controller continuously corrects a simple transform-limited field based on the instantaneous mismatch between two systems' responses - producing the required control on the fly, without prior waveform design. The framework is demonstrated on two distinct examples: a single-active-electron atom, where hydrogen is driven to mimic argon's strong-field optical emission, and a Fermi-Hubbard chain, where a weakly interacting lattice reproduces the transport dynamics of a Mott-insulating reference. By shifting the control paradigm from predesigned inputs to adaptive response tracking, this approach establishes closed-loop feedback as a broadly applicable route to programmable quantum dynamics.