Absence of superfluidity in a parahydrogen film intercalated within a crystal of Na atoms

TL;DR

This study uses Quantum Monte Carlo simulations to investigate parahydrogen films within a Na atom lattice, providing evidence that contradicts previous claims of superfluidity and showing the system remains a non-superfluid crystalline phase.

Contribution

It offers the first detailed numerical analysis demonstrating the absence of superfluidity in this specific parahydrogen system, challenging prior theoretical predictions.

Findings

The system forms a non-superfluid crystalline phase at low temperatures.

Quantum Monte Carlo simulations show no superfluid behavior.

Results suggest previous predictions of superfluidity were biased or incorrect.

Abstract

A recent claim of possible superfluid behaviour of parahydrogen films intercalated within a crystalline matrix of Na atoms is examined. Quantum Monte Carlo simulations at finite temperature yield strong numerical evidence that the system forms at low temperature a non-superfluid crystalline phase, commensurate with the underlying impurity lattice. The physics of this system is therefore qualitatively identical to that observed in similar settings, extensively studied in precedence. Comparison of numerical results obtained here, with those of the reference in which the prediction of superfluidity (disproven here) was made, points to likely bias in the computational methodology adopted therein.