Path-Optimized Fast Quasi-Adiabatic Driving in Coupled Elastic Waveguides

TL;DR

This paper extends the FAQUAD technique to optimize paths in two-dimensional parameter spaces for coupled elastic waveguides, enabling faster adiabatic energy transfer with experimental validation.

Contribution

It introduces a path-optimized FAQUAD framework for multidimensional adiabatic control, demonstrated in a coupled elastic-waveguide system.

Findings

Successful implementation of path optimization in a coupled elastic-waveguide system.

Direct experimental mapping of adiabatic energy transfer along optimized paths.

Enhanced control of waveguide parameters for efficient adiabatic processes.

Abstract

Fast quasi-adiabatic driving (FAQUAD) is a central technique in shortcuts to adiabaticity (STA), enabling accelerated adiabatic evolution by optimizing the rate of change of a single control parameter. However, many realistic systems are governed by multiple coupled parameters, where the adiabatic condition depends not only on the local rate of change but also on the path through parameter space. Here, we introduce an enhanced FAQUAD framework that incorporates path optimization in addition to conventional velocity optimization, extending STA control to two-dimensional parameter spaces. We implement this concept in a coupled elastic-waveguide system, where the synthetic parameters-detuning and coupling-are controlled by the thicknesses of the waveguides and connecting bridges. Using scanning laser Doppler vibrometry, we directly map the flexural-wave field and observe adiabatic energy transfer along the optimized path in parameter space. This elastic-wave platform provides a versatile classical analogue for exploring multidimensional adiabatic control, demonstrating efficient and compact implementation of shortcut-to-adiabaticity protocols.