Lian Zheng

Spin-Excitation-Instability-Induced Quantum Phase Transitions in Double-Layer Quantum Hall Systems

We study intersubband spin density collective modes in double-layer quantum Hall systems at

DOUBLE-LAYER QUANTUM HALL ANTIFERROMAGNETISM AT FILLING FRACTION V = 2/M WHERE M IS AN ODD INTEGER

\nu=2

COULOMB SCATTERING LIFETIME OF A TWO-DIMENSIONAL ELECTRON GAS

within the time-dependent Hartree-Fock approximation. We find that these intersubband spin density excitations may soften under experimentally accessible conditions, signaling a phase transition to a new quantum Hall state with interlayer inplane antiferromagnetic spin correlations. We show that this novel canted antiferromagnetic phase is energetically stable and that the phase transition is continuous.

Plasmon-pole approximation for semiconductor quantum-wire electrons

A low energy action for double-layer quantum Hall systems at filling fractions

ENERGY RELAXATION OF AN EXCITED ELECTRON GAS IN QUANTUM WIRES : MANY-BODY ELECTRON-LO-PHONON COUPLING

\nu = 2/m

Unusual temperature dependent resistivity of a semiconductor quantum wire

(

INELASTIC LIFETIMES OF CONFINED TWO-COMPONENT ELECTRON SYSTEMS IN SEMICONDUCTOR QUANTUM-WIRE AND QUANTUM-WELL STRUCTURES

m

CANTED ANTIFERROMAGNETIC AND SPIN-SINGLET QUANTUM HALL STATES IN DOUBLE-LAYER SYSTEMS

an odd integer) is introduced. Interlayer antiferromagnetic exchange induces a phase with canted spin order, and also a spin-singlet phase. Universal properties of zero and finite temperature transitions are obtained. We compute the critical temperature at which the canted order vanishes in a Kosterlitz-Thouless transition. Implications for recent light scattering experiments at

EXCHANGE INSTABILITIES IN SEMICONDUCTOR DOUBLE-QUANTUM-WELL SYSTEMS

\nu = 2

BILAYER TO MONOLAYER CHARGE-TRANSFER INSTABILITY IN SEMICONDUCTOR DOUBLE-QUANTUM-WELL STRUCTURES

are noted.