Superfluid density ρ<sub>S</sub>/ρ=Λ/Λ<sub>T</sub> [London] and specific heat ratio C<sub>S</sub>/C<sub>N</sub> in a superconductor
ORAL
Abstract
By the BCS framework [Bardeen, Cooper and Schrieffer, Phys. Rev., 108, 1175 (1957); Nam, Phys. Rev., 156, 470 (1967)] with a finite pairing interaction energy range Td to have a finite transition temperature Tc [Nam, Phys. Lett. A193, 111 (1994); (E) ibid A197, 458 (1995)], we present novel results: ρS/ρ[T=0]= tanh(G/2) =1-ρN/ρ, G= Σj (2/wj)tan-1(z/wj), wj=(π/2)j (odd integer), z=Td/2Tc, 1/G=N(0)V [the density of states/spin at a reference energy times the BCS pairing interaction energy]; CS/CN[T=0]=R(z) =(χS/χN) [12(z/π)2 + (1+2z)/(1+tanhz)], χS/χN =1-tanhz [spin susceptibility at T=0]; R(1.4)=0.496 may account for the data 0.5 in UTe2 [Ran et al, Science, 365, 684 (2019)]; R(BCS)=0; CS/CN[T=Tc]-1=d(z) =(6/π2) tanhz/[h(z)+(z-tanhz)/2z2], h(z)=Σj wj-3 tan-1(z/wj); d(z>>1) =12/7ζ(3) [BCS]; d(z<<1) =18/π2 [Nam, APSMAR21, M47.12]; Free energy difference (FN-FS)[T=0]= N(0)Δ2 tanhG/[1+tanhG], Δ=Td/sinhG. Superconducting state is a miscible liquid state with both ρS and ρN. Superconductors are multiconnected [Nam, Phys. Lett. A198, 447 (1995)].
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Presenters
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Sang-Boo Nam
Retired
Authors
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Sang-Boo Nam
Retired