skip to main content

DOE PAGESDOE PAGES

Title: Beyond triplet: Unconventional superconductivity in a spin-3/2 topological semimetal

In all known fermionic super fluids, Cooper pairs are composed of spin-1/2 quasi-particles that pair to form either spin-singlet or spin-triplet bound states. The "spin" of a Bloch electron, however, is xed by the symmetries of the crystal and the atomic orbitals from which it is derived, and in some cases can behave as if it were a spin-3/2 particle. The superconducting state of such a system allows pairing beyond spin-triplet, with higher spin quasi-particles combining to form quintet or even septet pairs. Here, we report evidence of unconventional superconductivity emerging from a spin-3/2 quasiparticle electronic structure in the half-Heusler semimetal YPtBi, a low-carrier density noncentrosymmetric cubic material with a high symmetry that preserves the p-like j = 3/2 manifold in the Bi-based Γ 8 band in the presence of strong spin-orbit coupling. With a striking linear temperature dependence of the London penetration depth, the existence of line nodes in the superconducting order parameter Δ is directly explained by a mixed-parity Cooper pairing model with high total angular momentum, consistent with a high-spin fermionic super fluid state. We propose a k ∙ p model of the j = 3/2 fermions to explain how a dominant J=3 septet pairing state ismore » the simplest solution that naturally produces nodes in the mixed even-odd parity gap. Together with the underlying topologically non-trivial band structure, the unconventional pairing in this system represents a truly novel form of super fluidity that has strong potential for leading the development of a new generation of topological superconductors.« less
Authors:
ORCiD logo [1] ;  [2] ;  [3] ;  [2] ; ORCiD logo [2] ; ORCiD logo [2] ;  [2] ; ORCiD logo [2] ; ORCiD logo [4] ;  [5] ;  [6] ; ORCiD logo [7] ; ORCiD logo [7] ; ORCiD logo [2]
  1. Univ. of Maryland, College Park, MD (United States); Ames Lab., Ames, IA (United States)
  2. Univ. of Maryland, College Park, MD (United States)
  3. Univ. of Maryland, College Park, MD (United States); Univ. of Central Florida, Orlando, FL (United States)
  4. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
  5. Univ. of Maryland, College Park, MD (United States); Univ. of Otago, Dunedin (New Zealand)
  6. Univ. of Wisconsin, Madison, WI (United States)
  7. Ames Lab., Ames, IA (United States)
Publication Date:
Report Number(s):
IS-J 9234
Journal ID: ISSN 2375-2548
Grant/Contract Number:
DMREF-1335215; SC-0010605; AC02-07CH11358; AC02-05CH11231; GBMF4419
Type:
Accepted Manuscript
Journal Name:
Science Advances
Additional Journal Information:
Journal Volume: 4; Journal Issue: 4; Journal ID: ISSN 2375-2548
Publisher:
AAAS
Research Org:
Ames Laboratory (AMES), Ames, IA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
OSTI Identifier:
1460308
Alternate Identifier(s):
OSTI ID: 1433652

Kim, Hyunsoo, Wang, Kefeng, Nakajima, Yasuyuki, Hu, Rongwei, Ziemak, Steven, Syers, Paul, Wang, Limin, Hodovanets, Halyna, Denlinger, Jonathan D., Brydon, Philip M. R., Agterberg, Daniel F., Tanatar, Makariy A., Prozorov, Ruslan, and Paglione, Johnpierre. Beyond triplet: Unconventional superconductivity in a spin-3/2 topological semimetal. United States: N. p., Web. doi:10.1126/sciadv.aao4513.
Kim, Hyunsoo, Wang, Kefeng, Nakajima, Yasuyuki, Hu, Rongwei, Ziemak, Steven, Syers, Paul, Wang, Limin, Hodovanets, Halyna, Denlinger, Jonathan D., Brydon, Philip M. R., Agterberg, Daniel F., Tanatar, Makariy A., Prozorov, Ruslan, & Paglione, Johnpierre. Beyond triplet: Unconventional superconductivity in a spin-3/2 topological semimetal. United States. doi:10.1126/sciadv.aao4513.
Kim, Hyunsoo, Wang, Kefeng, Nakajima, Yasuyuki, Hu, Rongwei, Ziemak, Steven, Syers, Paul, Wang, Limin, Hodovanets, Halyna, Denlinger, Jonathan D., Brydon, Philip M. R., Agterberg, Daniel F., Tanatar, Makariy A., Prozorov, Ruslan, and Paglione, Johnpierre. 2018. "Beyond triplet: Unconventional superconductivity in a spin-3/2 topological semimetal". United States. doi:10.1126/sciadv.aao4513. https://www.osti.gov/servlets/purl/1460308.
@article{osti_1460308,
title = {Beyond triplet: Unconventional superconductivity in a spin-3/2 topological semimetal},
author = {Kim, Hyunsoo and Wang, Kefeng and Nakajima, Yasuyuki and Hu, Rongwei and Ziemak, Steven and Syers, Paul and Wang, Limin and Hodovanets, Halyna and Denlinger, Jonathan D. and Brydon, Philip M. R. and Agterberg, Daniel F. and Tanatar, Makariy A. and Prozorov, Ruslan and Paglione, Johnpierre},
abstractNote = {In all known fermionic super fluids, Cooper pairs are composed of spin-1/2 quasi-particles that pair to form either spin-singlet or spin-triplet bound states. The "spin" of a Bloch electron, however, is xed by the symmetries of the crystal and the atomic orbitals from which it is derived, and in some cases can behave as if it were a spin-3/2 particle. The superconducting state of such a system allows pairing beyond spin-triplet, with higher spin quasi-particles combining to form quintet or even septet pairs. Here, we report evidence of unconventional superconductivity emerging from a spin-3/2 quasiparticle electronic structure in the half-Heusler semimetal YPtBi, a low-carrier density noncentrosymmetric cubic material with a high symmetry that preserves the p-like j = 3/2 manifold in the Bi-based Γ8 band in the presence of strong spin-orbit coupling. With a striking linear temperature dependence of the London penetration depth, the existence of line nodes in the superconducting order parameter Δ is directly explained by a mixed-parity Cooper pairing model with high total angular momentum, consistent with a high-spin fermionic super fluid state. We propose a k ∙ p model of the j = 3/2 fermions to explain how a dominant J=3 septet pairing state is the simplest solution that naturally produces nodes in the mixed even-odd parity gap. Together with the underlying topologically non-trivial band structure, the unconventional pairing in this system represents a truly novel form of super fluidity that has strong potential for leading the development of a new generation of topological superconductors.},
doi = {10.1126/sciadv.aao4513},
journal = {Science Advances},
number = 4,
volume = 4,
place = {United States},
year = {2018},
month = {4}
}