Spin injection from topological insulator into metal leads

P. P. Aseev, S. N. Artemenko

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We study theoretically helical edge and surface states of 2D and 3D topological insulators (TI) tunnel-coupled to metal leads and show that their transport properties are strongly affected by contacts as the latter play a role of a heat bath and induce damping and relaxation of electrons in the helical states of TI. A simple structure that produces a pure spin current in the external circuit is proposed. The current and the spin current delivered to the external circuit depend on the relation between characteristic lengths: decay length due to tunneling, contact length and, in case of 3D TI, mean free path and spin relaxation length caused by momentum scattering. If the decay length due to tunneling is the smallest one, then the electric and spin currents are of order of the conductance quantum in 2D TI, and of order of the conductance quantum multiplied by the ratio of the contact width to the Fermi wavelength in 3D TI. A role of electron-electron interaction is discussed in case of 2D TI, and it is shown that in contrast to the conventional Luttinger liquid picture the interaction can be treated perturbatively. The presence of interaction results in suppression of density of states at the Fermi level and hence in decrease of the electric and spin currents.

Original languageEnglish
Pages (from-to)222-226
Number of pages5
JournalPhysica B: Condensed Matter
Volume460
DOIs
Publication statusPublished - 1 Mar 2015

Fingerprint

Metals
insulators
injection
Electron-electron interactions
Networks (circuits)
Surface states
Fermi level
Transport properties
Momentum
Tunnels
Damping
Scattering
electric current
Wavelength
Electrons
Liquids
decay
mean free path
tunnels
baths

Keywords

  • Electron-electron interaction
  • Spin current
  • Topological insulator

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Cite this

Spin injection from topological insulator into metal leads. / Aseev, P. P.; Artemenko, S. N.

In: Physica B: Condensed Matter, Vol. 460, 01.03.2015, p. 222-226.

Research output: Contribution to journalArticle

@article{a5b6fb1b142349a295d5e962e81099eb,
title = "Spin injection from topological insulator into metal leads",
abstract = "We study theoretically helical edge and surface states of 2D and 3D topological insulators (TI) tunnel-coupled to metal leads and show that their transport properties are strongly affected by contacts as the latter play a role of a heat bath and induce damping and relaxation of electrons in the helical states of TI. A simple structure that produces a pure spin current in the external circuit is proposed. The current and the spin current delivered to the external circuit depend on the relation between characteristic lengths: decay length due to tunneling, contact length and, in case of 3D TI, mean free path and spin relaxation length caused by momentum scattering. If the decay length due to tunneling is the smallest one, then the electric and spin currents are of order of the conductance quantum in 2D TI, and of order of the conductance quantum multiplied by the ratio of the contact width to the Fermi wavelength in 3D TI. A role of electron-electron interaction is discussed in case of 2D TI, and it is shown that in contrast to the conventional Luttinger liquid picture the interaction can be treated perturbatively. The presence of interaction results in suppression of density of states at the Fermi level and hence in decrease of the electric and spin currents.",
keywords = "Electron-electron interaction, Spin current, Topological insulator",
author = "Aseev, {P. P.} and Artemenko, {S. N.}",
year = "2015",
month = "3",
day = "1",
doi = "10.1016/j.physb.2014.11.076",
language = "English",
volume = "460",
pages = "222--226",
journal = "Physica B: Condensed Matter",
issn = "0921-4526",
publisher = "Elsevier",

}

TY - JOUR

T1 - Spin injection from topological insulator into metal leads

AU - Aseev, P. P.

AU - Artemenko, S. N.

PY - 2015/3/1

Y1 - 2015/3/1

N2 - We study theoretically helical edge and surface states of 2D and 3D topological insulators (TI) tunnel-coupled to metal leads and show that their transport properties are strongly affected by contacts as the latter play a role of a heat bath and induce damping and relaxation of electrons in the helical states of TI. A simple structure that produces a pure spin current in the external circuit is proposed. The current and the spin current delivered to the external circuit depend on the relation between characteristic lengths: decay length due to tunneling, contact length and, in case of 3D TI, mean free path and spin relaxation length caused by momentum scattering. If the decay length due to tunneling is the smallest one, then the electric and spin currents are of order of the conductance quantum in 2D TI, and of order of the conductance quantum multiplied by the ratio of the contact width to the Fermi wavelength in 3D TI. A role of electron-electron interaction is discussed in case of 2D TI, and it is shown that in contrast to the conventional Luttinger liquid picture the interaction can be treated perturbatively. The presence of interaction results in suppression of density of states at the Fermi level and hence in decrease of the electric and spin currents.

AB - We study theoretically helical edge and surface states of 2D and 3D topological insulators (TI) tunnel-coupled to metal leads and show that their transport properties are strongly affected by contacts as the latter play a role of a heat bath and induce damping and relaxation of electrons in the helical states of TI. A simple structure that produces a pure spin current in the external circuit is proposed. The current and the spin current delivered to the external circuit depend on the relation between characteristic lengths: decay length due to tunneling, contact length and, in case of 3D TI, mean free path and spin relaxation length caused by momentum scattering. If the decay length due to tunneling is the smallest one, then the electric and spin currents are of order of the conductance quantum in 2D TI, and of order of the conductance quantum multiplied by the ratio of the contact width to the Fermi wavelength in 3D TI. A role of electron-electron interaction is discussed in case of 2D TI, and it is shown that in contrast to the conventional Luttinger liquid picture the interaction can be treated perturbatively. The presence of interaction results in suppression of density of states at the Fermi level and hence in decrease of the electric and spin currents.

KW - Electron-electron interaction

KW - Spin current

KW - Topological insulator

UR - http://www.scopus.com/inward/record.url?scp=84923875580&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84923875580&partnerID=8YFLogxK

U2 - 10.1016/j.physb.2014.11.076

DO - 10.1016/j.physb.2014.11.076

M3 - Article

AN - SCOPUS:84923875580

VL - 460

SP - 222

EP - 226

JO - Physica B: Condensed Matter

JF - Physica B: Condensed Matter

SN - 0921-4526

ER -