Low-temperature saturation of phase coherence length in topological insulators

Saurav Islam, Semonti Bhattacharyya, Hariharan Nhalil, Mitali Banerjee, Anthony Richardella, Abhinav Kandala, Diptiman Sen, Nitin Samarth, Suja Elizabeth, Arindam Ghosh

Research output: Contribution to journalArticle

Abstract

Implementing topological insulators as elementary units in quantum technologies requires a comprehensive understanding of the dephasing mechanisms governing the surface carriers in these materials, which impose a practical limit to the applicability of these materials in such technologies requiring phase coherent transport. To investigate this, we have performed magnetoresistance (MR) and conductance fluctuations (CF) measurements in both exfoliated and molecular beam epitaxy grown samples. The phase breaking length (lφ) obtained from MR shows a saturation below sample dependent characteristic temperatures, consistent with that obtained from CF measurements. We have systematically eliminated several factors that may lead to such behavior of lφ in the context of TIs, such as finite size effect, thermalization, spin-orbit coupling length, spin-flip scattering, and surface-bulk coupling. Our work indicates the need to identify an alternative source of dephasing that dominates at low T in topological insulators, causing saturation in the phase breaking length and time.

Original languageEnglish (US)
Article number245407
JournalPhysical Review B
Volume99
Issue number24
DOIs
StatePublished - Jun 13 2019

Fingerprint

phase coherence
Magnetoresistance
insulators
saturation
Molecular beam epitaxy
Orbits
molecular beam epitaxy
Scattering
orbits
Temperature
scattering
temperature

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Islam, S., Bhattacharyya, S., Nhalil, H., Banerjee, M., Richardella, A., Kandala, A., ... Ghosh, A. (2019). Low-temperature saturation of phase coherence length in topological insulators. Physical Review B, 99(24), [245407]. https://doi.org/10.1103/PhysRevB.99.245407
Islam, Saurav ; Bhattacharyya, Semonti ; Nhalil, Hariharan ; Banerjee, Mitali ; Richardella, Anthony ; Kandala, Abhinav ; Sen, Diptiman ; Samarth, Nitin ; Elizabeth, Suja ; Ghosh, Arindam. / Low-temperature saturation of phase coherence length in topological insulators. In: Physical Review B. 2019 ; Vol. 99, No. 24.
@article{47022e36e7604af09a4ff42462f8d3ac,
title = "Low-temperature saturation of phase coherence length in topological insulators",
abstract = "Implementing topological insulators as elementary units in quantum technologies requires a comprehensive understanding of the dephasing mechanisms governing the surface carriers in these materials, which impose a practical limit to the applicability of these materials in such technologies requiring phase coherent transport. To investigate this, we have performed magnetoresistance (MR) and conductance fluctuations (CF) measurements in both exfoliated and molecular beam epitaxy grown samples. The phase breaking length (lφ) obtained from MR shows a saturation below sample dependent characteristic temperatures, consistent with that obtained from CF measurements. We have systematically eliminated several factors that may lead to such behavior of lφ in the context of TIs, such as finite size effect, thermalization, spin-orbit coupling length, spin-flip scattering, and surface-bulk coupling. Our work indicates the need to identify an alternative source of dephasing that dominates at low T in topological insulators, causing saturation in the phase breaking length and time.",
author = "Saurav Islam and Semonti Bhattacharyya and Hariharan Nhalil and Mitali Banerjee and Anthony Richardella and Abhinav Kandala and Diptiman Sen and Nitin Samarth and Suja Elizabeth and Arindam Ghosh",
year = "2019",
month = "6",
day = "13",
doi = "10.1103/PhysRevB.99.245407",
language = "English (US)",
volume = "99",
journal = "Physical Review B-Condensed Matter",
issn = "2469-9950",
publisher = "American Physical Society",
number = "24",

}

Islam, S, Bhattacharyya, S, Nhalil, H, Banerjee, M, Richardella, A, Kandala, A, Sen, D, Samarth, N, Elizabeth, S & Ghosh, A 2019, 'Low-temperature saturation of phase coherence length in topological insulators', Physical Review B, vol. 99, no. 24, 245407. https://doi.org/10.1103/PhysRevB.99.245407

Low-temperature saturation of phase coherence length in topological insulators. / Islam, Saurav; Bhattacharyya, Semonti; Nhalil, Hariharan; Banerjee, Mitali; Richardella, Anthony; Kandala, Abhinav; Sen, Diptiman; Samarth, Nitin; Elizabeth, Suja; Ghosh, Arindam.

In: Physical Review B, Vol. 99, No. 24, 245407, 13.06.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Low-temperature saturation of phase coherence length in topological insulators

AU - Islam, Saurav

AU - Bhattacharyya, Semonti

AU - Nhalil, Hariharan

AU - Banerjee, Mitali

AU - Richardella, Anthony

AU - Kandala, Abhinav

AU - Sen, Diptiman

AU - Samarth, Nitin

AU - Elizabeth, Suja

AU - Ghosh, Arindam

PY - 2019/6/13

Y1 - 2019/6/13

N2 - Implementing topological insulators as elementary units in quantum technologies requires a comprehensive understanding of the dephasing mechanisms governing the surface carriers in these materials, which impose a practical limit to the applicability of these materials in such technologies requiring phase coherent transport. To investigate this, we have performed magnetoresistance (MR) and conductance fluctuations (CF) measurements in both exfoliated and molecular beam epitaxy grown samples. The phase breaking length (lφ) obtained from MR shows a saturation below sample dependent characteristic temperatures, consistent with that obtained from CF measurements. We have systematically eliminated several factors that may lead to such behavior of lφ in the context of TIs, such as finite size effect, thermalization, spin-orbit coupling length, spin-flip scattering, and surface-bulk coupling. Our work indicates the need to identify an alternative source of dephasing that dominates at low T in topological insulators, causing saturation in the phase breaking length and time.

AB - Implementing topological insulators as elementary units in quantum technologies requires a comprehensive understanding of the dephasing mechanisms governing the surface carriers in these materials, which impose a practical limit to the applicability of these materials in such technologies requiring phase coherent transport. To investigate this, we have performed magnetoresistance (MR) and conductance fluctuations (CF) measurements in both exfoliated and molecular beam epitaxy grown samples. The phase breaking length (lφ) obtained from MR shows a saturation below sample dependent characteristic temperatures, consistent with that obtained from CF measurements. We have systematically eliminated several factors that may lead to such behavior of lφ in the context of TIs, such as finite size effect, thermalization, spin-orbit coupling length, spin-flip scattering, and surface-bulk coupling. Our work indicates the need to identify an alternative source of dephasing that dominates at low T in topological insulators, causing saturation in the phase breaking length and time.

UR - http://www.scopus.com/inward/record.url?scp=85068834285&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85068834285&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.99.245407

DO - 10.1103/PhysRevB.99.245407

M3 - Article

AN - SCOPUS:85068834285

VL - 99

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 2469-9950

IS - 24

M1 - 245407

ER -