Bulletin of the American Physical Society
APS March Meeting 2018
Volume 63, Number 1
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session X04: Superconductivity in j=3/2 SemimetalsInvited
|
Hide Abstracts |
Sponsoring Units: DCMP Chair: Daniel Agterberg, Univ of Wisconsin, Milwaukee Room: LACC 151 |
Friday, March 9, 2018 8:00AM - 8:36AM |
X04.00001: High-spin superconductivity in topological half-Heusler semimetals Invited Speaker: Johnpierre Paglione In all known fermionic superfluids, Cooper pairs are composed of spin-1/2 quasi-particles that |
Friday, March 9, 2018 8:36AM - 9:12AM |
X04.00002: The fourth superconducting gap: intrinsic Bogoliubov Fermi surfaces Invited Speaker: Philip Brydon The superconductivity of cubic semimetals such as YPtBi represents a new paradigm for the interplay of Cooper pairing with strong spin-orbit coupling. The j=3/2 intrinsic angular momentum of the low-energy fermions leads to qualitative differences from the conventional theory of pairing between j=1/2 states. In particular, this permits Cooper pairs with quintet or septet total angular momentum, in addition to singlet and triplet states. Purely on-site interactions can generate s-wave quintet time-reversal symmetry-breaking states which mimic chiral d-wave gaps [1]; remarkably, however, the expected point and line nodes are replaced by intrinsic Fermi surfaces of Bogoliubov quasiparticles [2]. This effect arises from the strong spin-orbit coupling, which produces interband pairing potentials; these in turn generate an effective magnetic-field-like term, which “inflates” the point or line nodes into spheroids or tori, respectively. These Fermi surfaces can be energetically stable, and are topologically protected by particle-hole and inversion symmetries; “accidental” Fermi surfaces can also persist when inversion is weakly broken [3]. Our theory can be readily generalized to other systems where j=3/2 fermions are not present, e.g. URu2Si2 and SrPtAs, and so we expect these Fermi surfaces to be a ubiquitous feature of even-parity time-reversal symmetry-breaking superconductivity. |
Friday, March 9, 2018 9:12AM - 9:48AM |
X04.00003: Pairing of spin-3/2 carriers in three-dimensional a doped Luttinger semimetal: Confluence of topology, interaction and disorder Invited Speaker: Bitan Roy
|
Friday, March 9, 2018 9:48AM - 10:24AM |
X04.00004: Superconductivity in Three-Dimensional Spin-Orbit Coupled Semimetals Invited Speaker: Lucile Savary Motivated by the experimental detection of superconductivity in the low-carrier density half-Heusler compound YPtBi, we study the pairing instabilities of three-dimensional strongly spin-orbit coupled semimetals with a quadratic band touching point. In these semimetals the electronic |
Friday, March 9, 2018 10:24AM - 11:00AM |
X04.00005: Theory of complex tensor superconducting order in quadratic-band-touching Luttinger semimetals Invited Speaker: Igor Herbut We will discuss unconventional superconductivity in three dimensional electronic systems with the chemical potential close to the quadratic band touching point in the band dispersion. The latter arises when the bands are inverted due to strong spin-orbit coupling, in materials such as mercury telluride or half-Heuslers, for example. Featureless contact interaction can then lead to either a familiar s-wave, or an unconventional d-wave state, with five complex components that transform as irreducible symmetric second-rank tensor under rotations. The general structure of the Ginzburg-Landau free energy for such a three-dimensional d-wave state with an emphasis on its unusual features that stem from the complex tensorial nature of the order parameter will be further elucidated. The computation of the coefficients in the Ginzburg-Landau free energy implies that in the isotropic limit there remains a large residual symmetry-unrelated accidental degeneracy at the quartic-term level between different d-wave configurations, which is ultimately resolved only by the higher-order terms. For a vanishing chemical potential the ground state is the superconducting analogue of the uniaxial nematic, which features two parallel circular line nodes in the quasiparticle spectrum. At finite chemical potential and at weak coupling, however, time-reversal-symetry-broken superconducting states which contain fermi points and surfaces are energetically preferred. Some phenomenology of various superconducting states and possible connections to the penetration depth measurements in YPtBi will be explored. ( I. Boettcher and I. F. Herbut, arXiv:1707.03444) |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700