Ising Quantum Hall Ferromagnet in Magnetically Doped Quantum Wells

Abstract

We report on the observation of the Ising quantum Hall ferromagnet with Curie temperature T(C) as high as 2 K in a modulation-doped (Cd,Mn)Te heterostructure. In this system field-induced crossing of Landau levels occurs due to the giant spin-splitting effect. Magnetoresistance data, collected over a wide range of temperatures, magnetic fields, tilt angles, and electron densities, are discussed taking into account both Coulomb electron-electron interactions and s-d coupling to Mn spin fluctuations. The critical behavior of the resistance "spikes" at T-->T(C) corroborates theoretical suggestions that the ferromagnet is destroyed by domain excitations.

Magnetotransport in high-g-factor low-density two-dimensional electron systems confined inIn0.75Ga0.25Desrat1, Giazotto2, Pellegrini3 et al. 2004Phys. Rev. B354260View full textAdd to dashboardCite

“…Finally it must be stressed that at the coincidence angle the magneto-resistance R xx exhibits no spikes and no hysteresis at any filling factor. These effects which were reported in a number of material systems are associated to the formation of magnetic domains [25,27,28]. As proposed in Ref.…”

Magnetization of a two-dimensional electron gas with a second filled subband

“…Their study has lead to the discovery of many correlated quantum hall states, [2][3][4] and much effort is put into unravelling the energy-level structure of these systems.…”

Manipulation with Spin Ordering in Ferromagnetic Semiconductors

“…Importantly, by evaluating F c (q), the magnetic stiffness can be determined, which together with magnetic anisotropy, yield the dispersion of spin waves [15] and the structure of magnetic domains [16]. Owing to a relatively small magnitudes of the s-d exchange coupling and density of states, the carrier-induced ferromagnetism is expected [5] and observed only under rather restricted conditions in ntype DMS [17,18]. Since magnetic properties are controlled by the band carriers, the appealing possibility is to change the magnetic ordering isothermally, by light or by the electric field.…”