Spin-orbit proximity in van der Waals heterostructures

  1. Herling, Franz Peter
Supervised by:
  1. Luis Eduardo Hueso Arroyo Director
  2. Félix Casanova Fernández Director

Defence university: Universidad del País Vasco - Euskal Herriko Unibertsitatea

Fecha de defensa: 04 March 2022

Committee:
  1. Celia Rogero Blanco Chair
  2. Sergio Valenzuela Secretary
  3. Marko Burghard Committee member
Department:
  1. Física

Type: Thesis

Teseo: 157383 DIALNET lock_openADDI editor

Abstract

In this thesis, graphene/transition metal dichalcogenides van der Waals hetero-structures were used to develop a device that combines Hall probes with ferromagnetic electrodes. With it, the spin Hall effect in graphene induced by spin-orbit coupling proximity with MoS2 and WSe2 could unambiguously be demonstrated. The Hanle precession of the non-local resistance not only gives convincing experimental proof but also allows the quantification of the spin transport and the spin-to-charge conversion. The fact that both occur in different parts of the same material gives rise to a high efficiency for the voltage output up to room temperature. Additionally, the control by applying a gate voltage was shown in graphene proximitized with WSe2, enabling a record efficiency measured of around 40 nm. Additionally, in a graphene/WSe2 lateral spin valve, coherent, electrically controllable spin precession in the absence of an external magnetic field was achieved, even in the diffusive regime.