scholarly journals Evidence for even parity unconventional superconductivity in Sr2RuO4

2021 ◽  
Vol 118 (25) ◽  
pp. e2025313118
Author(s):  
Aaron Chronister ◽  
Andrej Pustogow ◽  
Naoki Kikugawa ◽  
Dmitry A. Sokolov ◽  
Fabian Jerzembeck ◽  
...  
Keyword(s):  
Ground State ◽  
Knight Shift ◽  
Superconducting Order Parameter ◽  
P Wave ◽  
Quarter Century ◽  
Field Dependent ◽  
Triplet Pairing ◽  
Parameter Symmetry ◽  
Order Parameter Symmetry ◽  
Superconducting Condensate

Unambiguous identification of the superconducting order parameter symmetry in Sr2RuO4 has remained elusive for more than a quarter century. While a chiral p-wave ground state analogue to superfluid 3He-A was ruled out only very recently, other proposed triplet-pairing scenarios are still viable. Establishing the condensate magnetic susceptibility reveals a sharp distinction between even-parity (singlet) and odd-parity (triplet) pairing since the superconducting condensate is magnetically polarizable only in the latter case. Here field-dependent 17O Knight shift measurements, being sensitive to the spin polarization, are compared to previously reported specific heat measurements for the purpose of distinguishing the condensate contribution from that due to quasiparticles. We conclude that the shift results can be accounted for entirely by the expected field-induced quasiparticle response. An upper bound for the condensate magnetic response of <10% of the normal state susceptibility is sufficient to exclude all purely odd-parity candidates.

Example of how an unconventional order parameter symmetry may open new perspectives in the design of HTS Josephson junctions

2002 ◽  
Author(s):  
Francesco Tafuri ◽  
Filomena Lombardi ◽  
F. M. Granozio ◽  
F. Carillo ◽  
Fabrizio Riccia ◽  
...  
Keyword(s):  
Josephson Junctions ◽  
Order Parameter ◽  
Parameter Symmetry ◽  
Order Parameter Symmetry

scholarly journals Optimal electronic doping in p-wave superconductors

2021 ◽  
Vol 67 (6 Nov-Dec) ◽  
Author(s):  
Benjamín Millan ◽  
Ivonne Judith Hernández ◽  
Luis Antonio Pérez ◽  
José Samuel Millan
Keyword(s):  
Critical Temperature ◽  
Ground State Energy ◽  
Electron Concentration ◽  
Ground State ◽  
State Energy ◽  
P Wave ◽  
Square Lattice ◽  
S Wave ◽  
Optimal Doping ◽  
D Wave

Recently, within a generalized Hubbard model which includes correlated nearest (∆t) and next-nearest hopping interactions (∆t_3 ), a comparative study between d- and s*- wave superconducting ground states on a square lattice was performed. It was found that the critical temperature of transition T_c (n), as a function of the electron concentration n, reaches a maximum (T_(c-max) at a given optimal doping (n_op) for each value of the ratio (t’)⁄t, where t and t’ are the tight-binding nearest and next-nearest hopping parameter of a square lattice, respectively. From all values obtained for T_(c-max) ((t’)⁄(t,n_op) a global minimum one was encountered for both symmetries. Likewise, in the same space, a minimal ground state energy E_g was also obtained. For d-wave channel both minima are localized around the same optimal doping, however, for s* symmetry, the two minima are located at different electron concentrations. In this work, we additionally study how the p-wave ground-state energy and the critical temperature depend on the hoppings parameters and the electron concentration. The results show that for p-wave, minimum global values of  and  in the space do exist too, they are found around half filling but, as occurs for s*- wave, the minimum of T_(c-max) does not occur at the same point as . Moreover, we present a ground-state phase diagram in the space (t’)⁄(t,n_op) where it is possible to find zones of coexistence and competition between the s*-, p- and d-wave symmetries. Also, an analysis of the shape of the Fermi surface and the single-particle energy, as functions of the wave vector of an electron in the Cooper pair, has been done for different regions of the mentioned space.

Anisotropic Order Parameter in Two-Band Superconductivity

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3099-3101 ◽  
Author(s):  
P. Konsin ◽  
N. Kristoffel ◽  
P. Rubin
Keyword(s):  
Order Parameter ◽  
Equation System ◽  
Order Parameters ◽  
Band Model ◽  
Gap Equation ◽  
Narrow Region ◽  
Interband Scattering ◽  
Parameter Symmetry ◽  
Order Parameter Symmetry

A two-overlapping band model of superconductivity with s+d interband scattering is investigated. The gap equation system has been solved numerically. Solutions of pure-d and -s, or of mixed s+d nature are possible. The pure Tcd(μ) or Tcs(μ) curves determine the onset of superconductivity with temperature lowering. In the under- and over-doped region pure-symmetry orderings are preferred. Mixed ordering can exist in a narrow region of μ, becoming narrower with T rising. The peculiarities of the and spectra are reflected in the behaviour of the order parameters. Order parameter symmetry can change with T and μ.

Sign in / Sign up

Export Citation Format

Share Document