Odd-frequency pairs in chiral symmetric systems: Spectral bulk-boundary correspondence and topological criticality
Sep 15, 201817 pages
Published in:
- Phys.Rev.B 99 (2019) 18, 184512
- Published: May 22, 2019
e-Print:
- 1809.05687 [cond-mat.supr-con]
View in:
Citations per year
Abstract: (APS)
Odd-frequency Cooper pairs with chiral symmetry emerging at the edges of topological superconductors are a useful physical quantity for characterizing the topological properties of these materials. In this work, we show that the odd-frequency Cooper pair amplitudes can be expressed by a winding number extended to a nonzero frequency, which is called a “spectral bulk-boundary correspondence,” and can be evaluated from the spectral features of the bulk. The odd-frequency Cooper pair amplitudes are classified into two categories: the amplitudes in the first category have the singular functional form ∼1/z (where z is a complex frequency) that reflects the presence of a topological surface Andreev bound state, whereas the amplitudes in the second category have the regular form ∼z and are regarded as nontopological. We discuss the topological phase transition by using the coefficient in the latter category, which undergoes a power-law divergence at the topological phase transition point and is used to indicate the distance to the critical point. These concepts are established based on several concrete models, including a Rashba nanowire system that is promising for realizing Majorana fermions.Note:
- 14 pages, 11 figures
- Superfluidity and superconductivity
References(76)
Figures(11)
- [1]
- [2]
- [3]
- [4]
- [5]
- [6]
- [7]
- [8]
- [9]
- [10]
- [11]
- [12]
- [13]
- [14]
- [15]
- [16]
- [17]
- [17]
- [18]
- [19]
- [20]
- [21]
- [22]
- [23]
- [24]