The molecular nature of superfluidity: Viscosity of helium from quantum stochastic molecular dynamics simulations over real trajectories

TL;DR

This paper investigates the molecular basis of superfluidity in helium-4 by using quantum stochastic molecular dynamics simulations, revealing a significant reduction in viscosity due to Bose-Einstein condensation and its implications for quantum mechanics interpretation.

Contribution

It introduces a novel simulation approach combining quantum equations of motion with stochastic molecular dynamics to study superfluidity at the molecular level.

Findings

Quantum liquid viscosity is nearly five times smaller than classical at low temperatures.

Superfluidity arises from Bose-Einstein condensation affecting molecular trajectories.

Results suggest real particle trajectories have implications for quantum mechanics interpretation.

Abstract

Using quantum equations of motion for interacting bosons, stochastic molecular dynamics simulations with quantized momenta are performed for Lennard-Jones helium-4. The viscosity of the quantum liquid is significantly less than that of the classical liquid, being almost 5 times smaller at the lowest temperature studied. The classical and quantum liquids are identical except for Bose-Einstein condensation, which pinpoints the molecular mechanism for superfluidity. The results rely on the existence of stochastic but real particle trajectories, which has implications for the interpretation of quantum mechanics.