Localization and the anomalous Hall effect in a dirty metallic ferromagnet

P. Mitra, N. Kumar, Nitin Samarth

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

We report magnetoresistance measurements over an extensive temperature range (0.1≤T≤100 K) in a disordered ferromagnetic semiconductor (Ga1-x Mnx As). The study focuses on a series of metallic Ga1-x Mnx As epilayers that lie in the vicinity of the metal-insulator transition (k Fle∼1). At low temperatures (T<4 K), we first confirm the results of earlier studies that the longitudinal conductivity shows a T1/3 dependence, consistent with quantum corrections from carrier localization in a "dirty" metal. In addition, we find that the anomalous Hall conductivity exhibits universal behavior in this temperature range with no pronounced quantum corrections. We argue that the observed scaling relationship between the low-temperature longitudinal and transverse resistivity, taken in conjunction with the absence of quantum corrections to the anomalous Hall conductivity, is consistent with the side-jump mechanism for the anomalous Hall effect. In contrast, at high temperatures (T≥4 K), neither the longitudinal nor the anomalous Hall conductivity exhibit universal behavior, indicating the dominance of inelastic-scattering contributions down to liquid-helium temperatures.

Original languageEnglish (US)
Article number035205
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume82
Issue number3
DOIs
StatePublished - Jul 9 2010

Fingerprint

Hall effect
conductivity
Temperature
liquid helium
metals
temperature
Helium
inelastic scattering
Inelastic scattering
Metal insulator transition
Epilayers
insulators
Magnetoresistance
scaling
electrical resistivity
Metals
Semiconductor materials
Liquids

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

@article{3f6e315863e14fedbfc6c0442ec9b177,
title = "Localization and the anomalous Hall effect in a dirty metallic ferromagnet",
abstract = "We report magnetoresistance measurements over an extensive temperature range (0.1≤T≤100 K) in a disordered ferromagnetic semiconductor (Ga1-x Mnx As). The study focuses on a series of metallic Ga1-x Mnx As epilayers that lie in the vicinity of the metal-insulator transition (k Fle∼1). At low temperatures (T<4 K), we first confirm the results of earlier studies that the longitudinal conductivity shows a T1/3 dependence, consistent with quantum corrections from carrier localization in a {"}dirty{"} metal. In addition, we find that the anomalous Hall conductivity exhibits universal behavior in this temperature range with no pronounced quantum corrections. We argue that the observed scaling relationship between the low-temperature longitudinal and transverse resistivity, taken in conjunction with the absence of quantum corrections to the anomalous Hall conductivity, is consistent with the side-jump mechanism for the anomalous Hall effect. In contrast, at high temperatures (T≥4 K), neither the longitudinal nor the anomalous Hall conductivity exhibit universal behavior, indicating the dominance of inelastic-scattering contributions down to liquid-helium temperatures.",
author = "P. Mitra and N. Kumar and Nitin Samarth",
year = "2010",
month = "7",
day = "9",
doi = "10.1103/PhysRevB.82.035205",
language = "English (US)",
volume = "82",
journal = "Physical Review B-Condensed Matter",
issn = "1098-0121",
publisher = "American Physical Society",
number = "3",

}

Localization and the anomalous Hall effect in a dirty metallic ferromagnet. / Mitra, P.; Kumar, N.; Samarth, Nitin.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 82, No. 3, 035205, 09.07.2010.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Localization and the anomalous Hall effect in a dirty metallic ferromagnet

AU - Mitra, P.

AU - Kumar, N.

AU - Samarth, Nitin

PY - 2010/7/9

Y1 - 2010/7/9

N2 - We report magnetoresistance measurements over an extensive temperature range (0.1≤T≤100 K) in a disordered ferromagnetic semiconductor (Ga1-x Mnx As). The study focuses on a series of metallic Ga1-x Mnx As epilayers that lie in the vicinity of the metal-insulator transition (k Fle∼1). At low temperatures (T<4 K), we first confirm the results of earlier studies that the longitudinal conductivity shows a T1/3 dependence, consistent with quantum corrections from carrier localization in a "dirty" metal. In addition, we find that the anomalous Hall conductivity exhibits universal behavior in this temperature range with no pronounced quantum corrections. We argue that the observed scaling relationship between the low-temperature longitudinal and transverse resistivity, taken in conjunction with the absence of quantum corrections to the anomalous Hall conductivity, is consistent with the side-jump mechanism for the anomalous Hall effect. In contrast, at high temperatures (T≥4 K), neither the longitudinal nor the anomalous Hall conductivity exhibit universal behavior, indicating the dominance of inelastic-scattering contributions down to liquid-helium temperatures.

AB - We report magnetoresistance measurements over an extensive temperature range (0.1≤T≤100 K) in a disordered ferromagnetic semiconductor (Ga1-x Mnx As). The study focuses on a series of metallic Ga1-x Mnx As epilayers that lie in the vicinity of the metal-insulator transition (k Fle∼1). At low temperatures (T<4 K), we first confirm the results of earlier studies that the longitudinal conductivity shows a T1/3 dependence, consistent with quantum corrections from carrier localization in a "dirty" metal. In addition, we find that the anomalous Hall conductivity exhibits universal behavior in this temperature range with no pronounced quantum corrections. We argue that the observed scaling relationship between the low-temperature longitudinal and transverse resistivity, taken in conjunction with the absence of quantum corrections to the anomalous Hall conductivity, is consistent with the side-jump mechanism for the anomalous Hall effect. In contrast, at high temperatures (T≥4 K), neither the longitudinal nor the anomalous Hall conductivity exhibit universal behavior, indicating the dominance of inelastic-scattering contributions down to liquid-helium temperatures.

UR - http://www.scopus.com/inward/record.url?scp=77956712483&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77956712483&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.82.035205

DO - 10.1103/PhysRevB.82.035205

M3 - Article

AN - SCOPUS:77956712483

VL - 82

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 1098-0121

IS - 3

M1 - 035205

ER -