Related papers: Collective excitations in a magnetically doped qua…
We consider collective excitations in graphene with filled Landau levels (LL's) in the presence of an external potential due to a single charged donor D+ or acceptor A- impurity. We show that localized collective modes split off the…
In Landau levels N > 1, the ground state of the two-dimensional electron gas (2DEG) in a perpendicular magnetic field evolves from a Wigner crystal for small filling of the partially filled Landau level, into a succession of bubble states…
A theory of magnetic impurities in a 2D electron gas quantized by a strong magnetic field is formulated in terms of Friedel-Anderson theory of resonance impurity scattering. It is shown that this scattering results in an appearance of bound…
An analytic closed form solution is derived for the bound states of electrons subject to a static, inhomogeneous ($1/r$-decaying) magnetic field, including the Zeeman interaction. The solution provides access to many-body properties of a…
A doped graphene layer in the integer quantum Hall regime reveals a highly unusual particle-hole excitation spectrum, which is calculated from the dynamical polarizability in the random phase approximation. We find that the elementary…
We study the density of states of two-dimensional electron gas in magnetic field with scattering on point-like impurities that are uniformly distributed along the sample. We show that the electron-impurity interaction completely lifts the…
Transport measurements under a tilted magnetic field were performed on a series of C-doped (001) AlGaAs/GaAs/AlGaAs two-dimensional hole samples. Due to a large g-factor, Zeeman energy is large and comparable to the cyclotron energy in…
Polarization-resolved magneto-luminescence, together with simultaneous magneto-transport measurements, have been performed on a two-dimensional electron gas (2DEG) confined in CdTe quantum well in order to determine the spin-splitting of…
We analyse the ground state properties of vertical double quantum dots in the lowest Landau level regime for filling factor \nu=2. This analysis follow two lines: on the one hand, we study the dispersion relation of different collective…
We present longitudinal and Hall magneto-resistance measurements of a ``magnetic'' two-dimensional electron gas (2DEG) formed in modulation-doped Zn$_{1-x-y}$Cd$_{x}$Mn$_{y}$Se quantum wells. The electron spin splitting is temperature and…
We report the observation of the fractional quantum Hall effect in the lowest Landau level of a two-dimensional electron system (2DES), residing in the diluted magnetic semiconductor Cd(1-x)Mn(x)Te. The presence of magnetic impurities…
Recent claims of an experimental demonstration of spontaneous spin polarisation in dilute electron gases \cite{young99} revived long standing theoretical discussions \cite{ceper99,bloch}. In two dimensions, the stabilisation of a…
We study quantum Hall ferromagnets in the presence of a random electrostatic impurity potential. Describing these systems with a classical non-linear sigma model and using analytical estimates supported by results from numerical…
Semiconductor interfaces, such as these existing in multilayer structures (e.g., quantum wells (QWs)), are interesting because of their ability to form 2D electron gases (2DEGs), in which charge carriers behave completely differently than…
We study the electric and magnetic properties of the edge of a two-dimensional electron gas in presence of a magnetic field and at filling factor unity. The existence of a spin textured edge is proved as a function of the Zeeman coupling…
This work elucidates the novel behavior found in a two-dimensional electron gas (2DEG) under a tilted magnetic field in which the field's angle becomes the dominant factor in tuning the spin-splitting rather than the strength of the…
Due to its extremely rich phase diagram, the two-dimensional electron gas exposed to perpendicular magnetic field has been the subject of intense and sustained study. One particularly interesting problem in this system is that of the…
The ground state phase diagram of two-dimensional electrons in high magnetic field is studied by the density matrix renormalization group (DMRG) method. The low energy excitations and pair correlation functions in Landau levels of N=0,1,2…
A brief summary of the emerging evidence for a new class of collective states of two-dimensional electrons in partially occupied excited Landau levels is presented. Among the most dramatic phenomena described are the large anisotropies of…
The density of states and the Hall conductivity of a two-dimensional electron gas in a uniform magnetic field and in the presence of a delta impurity are exactly calculated using elementary field theoretic techniques. Although these results…