Abstract
Time-reversal invariant superconductors in three dimensions may contain nodal lines in the Brillouin zone, which behave as Wilson loops of 3D momentum-space Chern-Simons theory of the Berry connection. Here we study the conditions of realizing linked nodal lines (Wilson loops), which yield a topological contribution to the thermal magnetoelectric coefficient that is given by the Chern-Simons action. We find the essential conditions are the existence of torus or higher genus Fermi surfaces and spiral spin textures. We construct such a model with two torus Fermi surfaces, where a generic spin-dependent interaction leads to double-helix-like linked nodal lines as the superconductivity is developed.
Original language | English (US) |
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Article number | 147001 |
Journal | Physical review letters |
Volume | 119 |
Issue number | 14 |
DOIs | |
State | Published - Oct 2 2017 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy