| 1. |
- Nakosai, Sho, et al.
(författare)
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Majorana Bound States and Nonlocal Spin Correlations in a Quantum Wire on an Unconventional Superconductor
- 2013
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 110:11, s. 117002-
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Tidskriftsartikel (refereegranskat)abstract
- We study theoretically the proximity effect of a one-dimensional metallic quantum wire (in the absence of spin-orbit interaction) lying on top of an unconventional superconductor. Three different material classes are considered as a substrate: (i) a chiral superconductor in class D with broken time-reversal symmetry and a class DIII superconductor (ii) with and (iii) without a nontrivial Z(2) number. Interestingly, we find degenerate zero energy Majorana bound states at both ends of the wire for all three cases. They are unstable against spin-orbit interaction in case (i), while they are topologically protected by time-reversal symmetry in cases (ii) and (iii). Remarkably, we show that nonlocal spin correlations between the two ends of the wire can be simply controlled by a gate potential in our setup. DOI: 10.1103/PhysRevLett.110.117002
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| 2. |
- Pershoguba, Sergey S., et al.
(författare)
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Skyrmion-induced bound states in a superconductor
- 2016
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Ingår i: PHYSICAL REVIEW B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 94:6
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Tidskriftsartikel (refereegranskat)abstract
- We consider a superconductor proximity coupled to a two-dimensional ferromagnetic film with a skyrmion texture. Using the T-matrix calculations and numerical modeling we calculate the spin-polarized local density of states in the superconductor in the vicinity of the skyrmion. We predict the skyrmion bound states that are induced in the superconductor, similar to the well-known Yu-Shiba-Rusinov states. The bound-state wave functions have spatial power-law decay. It is suggested that superconductivity could facilitate an effective long-range interaction between skyrmions when bound-state wave functions overlap.
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| 3. |
- Tamura, Shun, et al.
(författare)
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Bulk odd-frequency pairing in the superconducting Su-Schrieffer-Heeger model
- 2020
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Ingår i: Physical Review B. - 2469-9950 .- 2469-9969. ; 101:21
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Tidskriftsartikel (refereegranskat)abstract
- The Su-Schrieffer-Heeger model describes fermions that hop on a one-dimensional chain with staggered hopping amplitude, where the unit cell contains two sites, or two sublattices. In this work we consider the Su-Schrieffer-Heeger model with superconducting pairing and show that the sublattice index acts as an additional quantum number in the classification of Cooper pairs, giving rise to inter- and intrasublattice odd-frequency pair correlations in the bulk. Interestingly, this system behaves as a two-band superconductor where the bulk odd-frequency correlations depend solely on the intrinsic staggering properties of the model. In general, odd-frequency correlations coexist with even-frequency correlations in both the trivial and topological phases, with comparable and even larger odd-frequency amplitudes at the topological phase transition points at low frequencies, due to the closing of the energy gap at these points. Furthermore, we also discuss how bulk odd-frequency amplitudes are correlated with pseudogaps in the density of states and also with a charge density wave that appears due to the chemical potential imbalance between sublattices.
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