Quantum transport enabled by non-adiabatic transitions

¹ Department of Physics, Indian Institute of Science Education and Research Bhopal, Madhya Pradesh 462066, India
² Department of Physics, Christ College - Irinjalakuda, Kerala 680125, India
³ Max Planck Institute for the Physics of Complex Systems - Nöthnitzer Straße 38, D-01187 Dresden, Germany
⁴ Institute of Theoretical Physics, TUD Dresden University of Technology - D-01062, Dresden, Germany
⁵ Planqc GmbH - Münchenerstr. 34, D-85748 Garching, Germany

Received: 12 May 2025
Accepted: 30 July 2025

Abstract

Quantum transport of charge or energy in networks with discrete sites is central to diverse quantum technologies, from molecular electronics to light harvesting and quantum opto-mechanical metamaterials. A one-dimensional network can be viewed as a waveguide. We show that if such waveguide is hybridised with a control unit that contains a few sites, then transmission through the waveguide depends sensitively on the motion of the sites in the control unit. Together, the hybrid waveguide and its control unit form a Fano-Anderson chain whose Born-Oppenheimer surfaces inherit characteristics from both components: A bandstructure from the waveguide and potential energy steps as a function of site coordinates from the control unit. Using time-dependent quantum wavepackets, we reveal conditions under which the hybrid structure becomes transmissive only if the control unit contains mobile sites that induce non-adiabatic transitions between the surfaces. Hence, our approach provides functional synthetic Born-Oppenheimer surfaces for hybrid quantum technologies combining mechanic and excitonic elements, and has possible applications such as switching and temperature sensing.