Thermo-mechanical effects in majorana type quantum devices

We have developed a multi-scale model, consisting of an atomistic model in LAMMPS of an InSb nanowire, and a continuum model in COMSOL of a socalled Majorana research device, to study the effects of thermo-mechanical deformations during the cool down from room temperature to the operating temperature of about 50 mK. For the simulation of the InSb nano-wire suitable potentials were implemented in LAMMPS. The simulation results of the nano-wire show size dependent Young´s moduli and gradients in the radial lattice spacing during uniaxial straining. The materials properties that were derived from the atomistic model, were introduced in the continuum model. Cool down of the device from room temperature to it´s operating temperature introduced significant deformation. However, the stresses in the system are moderate and no fracture or damage is expected. Still, deformation of the device will induce shifts in band gap behavior of the device. Band gap shifts using a simple approximation are estimated to be about 34%.