Universal behavior of the BCS energy gap

J Henheik, AB kgaard Lauritsen - Journal of Spectral Theory, 2025 - ems.press
the BCS order parameter) at all temperatures 0 Ä T Ä Tc up to the critical one, Tc, and show
that, in the limit of weak coupling, the ratio „. T/= Tc is given by a universal function of the …

BCS Critical Temperature on Half-Spaces

B Roos, R Seiringer - arxiv preprint arxiv:2306.05824, 2023 - arxiv.org
We study the BCS critical temperature on half-spaces in dimensions $ d= 1, 2, 3$ with
Dirichlet or Neumann boundary conditions. We prove that the critical temperature on a half …

Enhanced BCS Superconductivity at a Corner

B Roos, R Seiringer - arxiv preprint arxiv:2308.07115, 2023 - arxiv.org
We consider the critical temperature for superconductivity, defined via the linear BCS
equation. We prove that at weak coupling the critical temperature for a sample confined to a …

Linear criterion for an upper bound on the BCS critical temperature

B Roos - arxiv preprint arxiv:2407.00796, 2024 - arxiv.org
Since BCS theory of superconductivity is non-linear, it is difficult to study superconducting
properties analytically. There is a more tractable linear criterion which determines a …

Multi-band superconductors have enhanced critical temperatures

J Henheik, E Langmann, AB Lauritsen - arxiv preprint arxiv:2409.17297, 2024 - arxiv.org
We introduce a multi-band BCS free energy functional and prove that for a multi-band
superconductor the effect of inter-band coupling can only increase the critical temperature …

Linear criterion for an upper bound on the Bardeen-Cooper-Schrieffer critical temperature

B Roos - Journal of Mathematical Physics, 2025 - pubs.aip.org
Since Bardeen-Cooper-Schrieffer theory of superconductivity is non-linear, it is difficult to
study superconducting properties analytically. There is a more tractable linear criterion …

On the mean-field antiferromagnetic gap for the half-filled 2D Hubbard model at zero temperature

E Langmann, J Lenells - arxiv preprint arxiv:2501.18141, 2025 - arxiv.org
We consider the antiferromagnetic gap for the half-filled two-dimensional (2D) Hubbard
model (on a square lattice) at zero temperature in Hartree-Fock theory. It was conjectured by …

Boundary superconductivity in BCS theory

B Roos - 2023 - research-explorer.ista.ac.at
Superconductivity has many important applications ranging from levitating trains over qubits
to MRI scanners. The phenomenon is successfully modeled by Bardeen-Cooper-Schrieffer …