Disorder-induced decoupled surface transport channels in thin films of doped topological insulators

Hanbum Park, Jimin Chae, Kwangsik Jeong, Hyejin Choi, Jaehun Jeong, Dasol Kim, Mann-Ho Cho

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Nonideal topological insulator (TI) films in which the bulk states are not insulating due to unintentional doping exhibit strong surface-bulk coupling. Such surface-bulk coupling can further induce intersurface coupling that affects the electrical conductivity of the TI films through a quantum interference effect known as weak antilocalization. Increased understanding and control of intersurface coupling is therefore crucial for the use of TI-based quantum devices. In this report on the transport properties of doped Bi2Se3 films under perpendicular and parallel magnetic fields, we observe a crossover between coupled and decoupled surface channels that is mediated by intentional disorder controlled by a post-annealing process. The intentional disorder causes the surface state carriers to rapidly lose their quantum phase and coherence, and as a result, more disordered Bi2Se3 films exhibit a shorter penetration depth of the surface state into the bulk states and weaker intersurface coupling, even though stronger surface-bulk coupling is expected. In previous studies, the role of disorder has generally been considered by determining its effect on surface-bulk scattering, but our results indicate that the role of disorder must be considered as a source of decoherence.

Original languageEnglish
Article number045411
JournalPhysical Review B
Volume98
Issue number4
DOIs
Publication statusPublished - 2018 Jul 12

Fingerprint

insulators
disorders
Thin films
thin films
Surface states
Transport properties
Doping (additives)
Scattering
Annealing
Magnetic fields
crossovers
penetration
transport properties
interference
electrical resistivity
annealing
causes
scattering
magnetic fields

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Park, Hanbum ; Chae, Jimin ; Jeong, Kwangsik ; Choi, Hyejin ; Jeong, Jaehun ; Kim, Dasol ; Cho, Mann-Ho. / Disorder-induced decoupled surface transport channels in thin films of doped topological insulators. In: Physical Review B. 2018 ; Vol. 98, No. 4.
@article{08b06b7a8b3a4a7c92a1c1e97e5f6366,
title = "Disorder-induced decoupled surface transport channels in thin films of doped topological insulators",
abstract = "Nonideal topological insulator (TI) films in which the bulk states are not insulating due to unintentional doping exhibit strong surface-bulk coupling. Such surface-bulk coupling can further induce intersurface coupling that affects the electrical conductivity of the TI films through a quantum interference effect known as weak antilocalization. Increased understanding and control of intersurface coupling is therefore crucial for the use of TI-based quantum devices. In this report on the transport properties of doped Bi2Se3 films under perpendicular and parallel magnetic fields, we observe a crossover between coupled and decoupled surface channels that is mediated by intentional disorder controlled by a post-annealing process. The intentional disorder causes the surface state carriers to rapidly lose their quantum phase and coherence, and as a result, more disordered Bi2Se3 films exhibit a shorter penetration depth of the surface state into the bulk states and weaker intersurface coupling, even though stronger surface-bulk coupling is expected. In previous studies, the role of disorder has generally been considered by determining its effect on surface-bulk scattering, but our results indicate that the role of disorder must be considered as a source of decoherence.",
author = "Hanbum Park and Jimin Chae and Kwangsik Jeong and Hyejin Choi and Jaehun Jeong and Dasol Kim and Mann-Ho Cho",
year = "2018",
month = "7",
day = "12",
doi = "10.1103/PhysRevB.98.045411",
language = "English",
volume = "98",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "4",

}

Disorder-induced decoupled surface transport channels in thin films of doped topological insulators. / Park, Hanbum; Chae, Jimin; Jeong, Kwangsik; Choi, Hyejin; Jeong, Jaehun; Kim, Dasol; Cho, Mann-Ho.

In: Physical Review B, Vol. 98, No. 4, 045411, 12.07.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Disorder-induced decoupled surface transport channels in thin films of doped topological insulators

AU - Park, Hanbum

AU - Chae, Jimin

AU - Jeong, Kwangsik

AU - Choi, Hyejin

AU - Jeong, Jaehun

AU - Kim, Dasol

AU - Cho, Mann-Ho

PY - 2018/7/12

Y1 - 2018/7/12

N2 - Nonideal topological insulator (TI) films in which the bulk states are not insulating due to unintentional doping exhibit strong surface-bulk coupling. Such surface-bulk coupling can further induce intersurface coupling that affects the electrical conductivity of the TI films through a quantum interference effect known as weak antilocalization. Increased understanding and control of intersurface coupling is therefore crucial for the use of TI-based quantum devices. In this report on the transport properties of doped Bi2Se3 films under perpendicular and parallel magnetic fields, we observe a crossover between coupled and decoupled surface channels that is mediated by intentional disorder controlled by a post-annealing process. The intentional disorder causes the surface state carriers to rapidly lose their quantum phase and coherence, and as a result, more disordered Bi2Se3 films exhibit a shorter penetration depth of the surface state into the bulk states and weaker intersurface coupling, even though stronger surface-bulk coupling is expected. In previous studies, the role of disorder has generally been considered by determining its effect on surface-bulk scattering, but our results indicate that the role of disorder must be considered as a source of decoherence.

AB - Nonideal topological insulator (TI) films in which the bulk states are not insulating due to unintentional doping exhibit strong surface-bulk coupling. Such surface-bulk coupling can further induce intersurface coupling that affects the electrical conductivity of the TI films through a quantum interference effect known as weak antilocalization. Increased understanding and control of intersurface coupling is therefore crucial for the use of TI-based quantum devices. In this report on the transport properties of doped Bi2Se3 films under perpendicular and parallel magnetic fields, we observe a crossover between coupled and decoupled surface channels that is mediated by intentional disorder controlled by a post-annealing process. The intentional disorder causes the surface state carriers to rapidly lose their quantum phase and coherence, and as a result, more disordered Bi2Se3 films exhibit a shorter penetration depth of the surface state into the bulk states and weaker intersurface coupling, even though stronger surface-bulk coupling is expected. In previous studies, the role of disorder has generally been considered by determining its effect on surface-bulk scattering, but our results indicate that the role of disorder must be considered as a source of decoherence.

UR - http://www.scopus.com/inward/record.url?scp=85050460136&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85050460136&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.98.045411

DO - 10.1103/PhysRevB.98.045411

M3 - Article

VL - 98

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 4

M1 - 045411

ER -