---
abstract: 'We investigate spatial adiabatic passage processes for sound waves propagation in sonic crystals, consisting of steel cylinders embedded in a water host medium, that present two linear defects. This work constitutes an extension of the well-known quantum optical rapid adiabatic passage technique to the field of sound propagation. Several spatial adiabatic passage devices are proposed, by appropriately designing the geometry of the two linear defects along the propagation direction, to work as a coherent multifrequency adiabatic splitter, a phase difference analyzer and a coherent multifrequency adiabatic coupler. These devices are robust in front of fluctuations of the geometric parameter values.'
author:
- 'R. Menchon-Enrich, J. Mompart and V. Ahufinger'
title: Spatial adiabatic passage processes in sonic crystals with linear defects
---

Introduction
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A unique feature of the adiabatic passage processes, which consist in the adiabatic following of an eigenvector of a system, is their working robustness against fluctuations of the parameter values. Adiabatic passage processes have been successfully studied in several areas of physics, such as Quantum Optics, Ultracold Atoms, and light propagation in coupled waveguide systems. In Quantum Optics, two techniques have been extensively studied, the so-called stimulated Raman adiabatic passage [@bergmann_coherent_1998] (STIRAP) and the rapid 