Abstract
Measurements of the low-frequency electrical noise in the ferromagnetic semiconductor (Ga,Mn)As reveal an enhanced integrated noise at low temperature. For moderate localization, we find a 1/f normalized power spectrum density over the entire range of temperatures studied (4.2 K<T<70 K). However, for stronger localization and a high density of Mn interstitials, we observe Lorentzian noise spectra accompanied by random telegraph noise. Magnetic field dependence and annealing studies suggest that interstitial Mn defects couple with substitutional Mn atoms to form nanoscale magnetic clusters characterized by a net moment of ∼20 μB whose fluctuations modulate hole transport.
| Original language | English (US) |
|---|---|
| Article number | 201201 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 76 |
| Issue number | 20 |
| DOIs | |
| State | Published - Nov 5 2007 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
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Random telegraph noise from magnetic nanoclusters in the ferromagnetic semiconductor (Ga,Mn)As. / Zhu, M.; Li, X.; Xiang, G.; Samarth, N.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 76, No. 20, 201201, 05.11.2007.Research output: Contribution to journal › Article
TY - JOUR
T1 - Random telegraph noise from magnetic nanoclusters in the ferromagnetic semiconductor (Ga,Mn)As
AU - Zhu, M.
AU - Li, X.
AU - Xiang, G.
AU - Samarth, N.
PY - 2007/11/5
Y1 - 2007/11/5
N2 - Measurements of the low-frequency electrical noise in the ferromagnetic semiconductor (Ga,Mn)As reveal an enhanced integrated noise at low temperature. For moderate localization, we find a 1/f normalized power spectrum density over the entire range of temperatures studied (4.2 K<T<70 K). However, for stronger localization and a high density of Mn interstitials, we observe Lorentzian noise spectra accompanied by random telegraph noise. Magnetic field dependence and annealing studies suggest that interstitial Mn defects couple with substitutional Mn atoms to form nanoscale magnetic clusters characterized by a net moment of ∼20 μB whose fluctuations modulate hole transport.
AB - Measurements of the low-frequency electrical noise in the ferromagnetic semiconductor (Ga,Mn)As reveal an enhanced integrated noise at low temperature. For moderate localization, we find a 1/f normalized power spectrum density over the entire range of temperatures studied (4.2 K<T<70 K). However, for stronger localization and a high density of Mn interstitials, we observe Lorentzian noise spectra accompanied by random telegraph noise. Magnetic field dependence and annealing studies suggest that interstitial Mn defects couple with substitutional Mn atoms to form nanoscale magnetic clusters characterized by a net moment of ∼20 μB whose fluctuations modulate hole transport.
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U2 - 10.1103/PhysRevB.76.201201
DO - 10.1103/PhysRevB.76.201201
M3 - Article
AN - SCOPUS:35848966381
VL - 76
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 20
M1 - 201201
ER -