Entangled end states with fractionalized spin projection in a time-reversal-invariant topological superconducting wire
We study the ground state and low-energy subgap excitations of a finite wire of a time-reversalinvariant topological superconductor (TRITOPS) with spin-orbit coupling. We solve the problem analytically for a long chain of a specific one-dimensional lattice model in the electron-hole symmetric config...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2018 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/177794 |
| Acceso en línea: | http://hdl.handle.net/11336/177794 |
| Access Level: | acceso abierto |
| Palabra clave: | Topological Superconductivity Majorana Excitations https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Sumario: | We study the ground state and low-energy subgap excitations of a finite wire of a time-reversalinvariant topological superconductor (TRITOPS) with spin-orbit coupling. We solve the problem analytically for a long chain of a specific one-dimensional lattice model in the electron-hole symmetric configuration and numerically for other cases of the same model. We present results for the spin density of excitations in long chains with an odd number of particles. The total spin projection along the axis of the spin-orbit coupling Sz = ±1/2 is distributed with fractions ±1/4 localized at both ends, and shows even-odd alternation along the sites of the chain. We calculate the localization length of these excitations and find that it can be well approximated by a simple analytical expression. We show that the energy E of the lowest subgap excitations of the finite chain defines tunneling and entanglement between end states. We discuss the effect of a Zeeman coupling ∆Z on one of the ends of the chain only. For ∆Z < E, the energy difference of excitations with opposite spin orientation is ∆Z /2, consistent with a spin projection ±1/4. We argue that these physical features are not model dependent and can be experimentally observed in TRITOPS wires under appropriate conditions. |
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