Share Email Print
cover

Proceedings Paper

Resistance noise study in a dirty quantum Hall ferromagnet
Author(s): Jan J. Jaroszynski; T. Andrearczyk; J. Wrobel; Greg Karczewski; T. Wojtowicz; Dragana Popovic; Tomasz Dietl
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

A giant and nonlinear Zeeman splitting in diluted magnetic semiconductors (DMS) offers a unique opportunity to examine quantum Hall ferromagnetism (QHF) since crossing of Landau levels (LL) can be achieved in moderately strong (Btot ≈ 1 T) total magnetic fields. We carried out magnetoresistance studies on modulation-doped, gated heterostructures of Cd1-xMnxTe/Cd1-yMgyTe:I. We put into evidence the formation of ISing quantum Hall ferromagnet with Curie temperature Tc as high as 2 K. QHF in our device is manisfested by anomalous magnetoresistance maxima, their hysteretic behavior, and time-dependent resistance, similar to earlier observations in III-V heterostructures. However, in our system these phenomena are much stronger, especially when either 2- or 1-, and 0+ LL are brought into coincidence. The magnitude of the QHF spikes depends dramatically on the history of the sample, shows hysteresis when either magnetic field or gate voltage are swept, stretched exponential-time evolution characteristic of glassy systems, and strong Barkhausen noise reflecting the dynamics of ferromagnetic domains. Our study indicates that these metastabilities stem from the electronic systems itself as an effect of slow dynamics of ferromagnetic domains, while the nuclear spin polarization plays a rather minor role.

Paper Details

Date Published: 9 May 2003
PDF: 9 pages
Proc. SPIE 5112, Noise as a Tool for Studying Materials, (9 May 2003); doi: 10.1117/12.496968
Show Author Affiliations
Jan J. Jaroszynski, National High Magnetic Field Lab. (United States)
Institute of Physics, Polish Academy of Sciences (United States)
T. Andrearczyk, National High Magnetic Field Lab. (United States)
Institute of Physics, Polish Academy of Sciences (Poland)
J. Wrobel, Institute of Physics, Polish Academy of Sciences (Poland)
Greg Karczewski, Institute of Physics, Polish Academy of Sciences (Poland)
T. Wojtowicz, Institute of Physics, Polish Academy of Sciences (Poland)
Dragana Popovic, National High Magnetic Field Lab. (United States)
Tomasz Dietl, Institute of Physics, Polish Academy of Sciences (Poland)


Published in SPIE Proceedings Vol. 5112:
Noise as a Tool for Studying Materials
Michael B. Weissman; Nathan E. Israeloff; A. Shulim Kogan, Editor(s)

© SPIE. Terms of Use
Back to Top