Quantum Monte Carlo simulation of superfluid helium confined inside pre-plated nanoporous materials

Abstract

In one spatial dimension, enhanced thermal and quantum fluctuations should preclude the existence of any long range ordered superfluid phase of matter. Mesoporous ordered silica-based structures such as the molecular sieve MCM-41 offer an experimental route towards the observation of this effect through the physical confinement of superfluid helium inside quasi-one-dimensional channels. However, the angstrom-scale coherence length of the wavefunction away from the bulk superfluid transition temperature requires novel nano-engineering approaches to reach the one-dimensional limit. In this talk we will describe ab initio quantum Monte Carlo simulations of superfluid helium confined inside MCM-41 that has been pre-plated with adsorbates to reduce the diameter of the confining media. We will describe how the choice of adsorbate (e.g. argon, neon, krypton) can be modified to obtain different types of helium structures inside the pores. Phase and density correlations may be further tuned via the external pressure of helium with the goal of realizing an emergent one-dimensional quantum liquid.

Nathan Nichols

Graduate Student in Materials Science

My research interests include low dimensional exotic phases of matter, quantum Monte Carlo algorithmic development, and machine learning for the quantum many-body problem.