1. Flat bands as a route to high-temperature superconductivity in graphite
- Author
-
Heikkila, Tero T. and Volovik, Grigori E.
- Subjects
Superconductivity (cond-mat.supr-con) ,Condensed Matter - Materials Science ,Condensed Matter::Superconductivity ,Condensed Matter - Superconductivity ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences - Abstract
Superconductivity is traditionally viewed as a low-temperature phenomenon. Within the BCS theory this is understood to result from the fact that the pairing of electrons takes place only close to the usually two-dimensional Fermi surface residing at a finite chemical potential. Because of this, the critical temperature is exponentially suppressed compared to the microscopic energy scales. On the other hand, pairing electrons around a dispersionless (flat) energy band leads to very strong superconductivity, with a mean-field critical temperature linearly proportional to the microscopic coupling constant. The prize to be paid is that flat bands can generally be generated only on surfaces and interfaces, where high-temperature superconductivity would show up. The flat-band character and the low dimensionality also mean that despite the high critical temperature such a superconducting state would be subject to strong fluctuations. Here we discuss the topological and non-topological flat bands discussed in different systems, and show that graphite is a good candidate for showing high-temperature flat-band interface superconductivity., Submitted as a chapter to the book on "Basic Physics of functionalized Graphite", 21 pages, 12 figures
- Published
- 2015