Finite-size effects on the thermal conductivity of ^4He near T_\lambda

TL;DR

This paper uses a renormalization-group approach to analyze the finite-size effects on the thermal conductivity of confined helium-4 near the superfluid transition temperature, comparing theoretical predictions with experimental data.

Contribution

It provides a theoretical calculation of thermal conductivity in confined helium-4 near T_mbda using model F with boundary conditions, without adjustable parameters.

Findings

Theoretical results agree with experimental data.

Finite-size effects significantly influence thermal conductivity near T_mbda.

Model accurately captures boundary condition impacts on heat transport.

Abstract

We present results of a renormalization-group calculation of the thermal conductivity of confined $\rm^4$He in a $L^2 \times \infty$ geometry above and at $T_\lambda$ within model F with Dirichlet boundary conditions for the order parameter. We assume a heat flow parallel to the boundaries which implies Neumann boundary conditions for the entropy density. No adjustable parameters other than those known from bulk theory and static finite-size theory are used. Our theoretical results are compared with experimental data by Kahn and Ahlers.