Ultrasound attenuation due to order parameter collective modes in impure anisotropic P-wave superconductors

1987 ◽  
Vol 63 (11) ◽  
pp. 1027-1031 ◽  
Author(s):  
H. Monien ◽  
L. Tewordt ◽  
K. Scharnberg
1987 ◽  
Vol 26 (S3-2) ◽  
pp. 1215 ◽  
Author(s):  
Hartmut Monien ◽  
Ludwig Tewordt ◽  
Kurt Scharnberg

2021 ◽  
Author(s):  
Peter Brusov ◽  
Tatiana Filatova

The main parameter, which describes superfluids and superconductors and all their main properties is the order parameter. After discovery the high temperature superconductors (HTSC) and heavy fermion superconductors (HFSC) the unconventional pairing in different superconductors is studied very intensively. The main problem here is the type of pairing: singlet or triplet, orbital moment of Cooper pair value L, symmetry of the order parameter etc. Recent experiments in Sr2RuO4 renewed interest in the problem of the symmetry of the order parameters of the HTSC. The existence of CuO2 planes – the common structural factor of HTSC – suggests we consider two-dimensional (2D) models. A 2D– model of p–pairing using a path integration technique has been developed by Brusov and Popov. A 2D model of d–pairing within the same technique has been developed by Brusov et al. All properties of 2D–superconductors (for example, of CuO2 planes of HTSC) and, in particular, the collective excitations spectrum, are determined by these functionals. We consider all superconducting states, arising in symmetry classification of p-wave and d-wave 2D–superconductors, and calculate the full collective modes spectrum for each of these states. This will help to identify the type of pairing and the symmetry of the order parameter in HTSC and HFSC.


2002 ◽  
Vol 16 (03) ◽  
pp. 453-461 ◽  
Author(s):  
GRZEGORZ LITAK

The effect of nonmagnetic disorder on the pairing amplitude is studied by means of a perturbation method. Using an extended one band Hubbard model with an intersite attraction we analyze various solutions of p-wave pairing symmetry and discuss their instability calculating fluctuations of order parameter. The model is applied to describe the effect of disorder in Sr2RuO4. The results shows that the real solution with line nodes can be favoured by disorder.


2004 ◽  
Vol 16 (02) ◽  
pp. 147-174 ◽  
Author(s):  
STAN ALAMA ◽  
LIA BRONSARD

We consider a two-dimensional Ginzburg–Landau model for superconductors which exhibit ferromagnetic ordering in the superconducting phase, introduced by physicists to describe unconventional p-wave superconductors. In this model the magnetic field is directly coupled to a vector-valued order parameter in the energy functional. We show that one effect of spin coupling is to increase the second critical field Hc2, the value of the applied magnetic field at which superconductivity is lost in the bulk. Indeed, when the spin coupling is strong we show that the upper critical field is no longer present, confirming predictions in the physics literature. We treat the energy density as a measure, and show that the order parameter converges (as the Ginzburg–Landau parameter κ→∞) in an average sense to a constant determined by the average energy.


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