Orbital Effects of Strong Magnetic Field on a 2-D Holstein Polaron

TL;DR

This study explores how strong magnetic fields influence the properties of a 2D Holstein polaron, revealing that magnetic flux can tune polaron size and affect its ground state characteristics.

Contribution

It introduces a variational approach based on exact diagonalization to analyze magnetic effects on 2D Holstein polarons, highlighting magnetic field as a tuning parameter.

Findings

Magnetic field impacts polaron properties across all regimes.

Loosely bound polarons are more affected by magnetic fields.

Magnetic flux can reduce the size of large polarons.

Abstract

We investigate the orbital effects of strong external magnetic field on the ground state properties of a two dimensional holstein polaron, employing variational approaches based on the exact diagonalization (VAED). From the ground state energy and the wave function we calculate electron-phonon correlation function, the average phonon number and the Drude weight and investigate the evolution of a 2D holstein polaron as a function of the magnetic flux. Although the external magnetic field affects the polaron throughout the parameter regime, we show that the magnetic field has a stronger effect on a loosely bound (spatially extended) polaron. We also find that the magnetic field can be used as a tuning parameter, particularly for weakly coupled polaron, to reduce the spatial extent of a large polaron.