Physics – Condensed Matter
Scientific paper
1996-09-19
Physics
Condensed Matter
24 pages, figures included. Also available at http://www-cmg.physics.umd.edu/~lzheng/preprint/ct.uu/ . Revised final version
Scientific paper
10.1103/PhysRevB.55.4506
We consider various exchange-driven electronic instabilities in semiconductor double-layer systems in the absence of any external magnetic field. We establish that there is no exchange-driven bilayer to monolayer charge transfer instability in the double-layer systems. We show that, within the unrestricted Hartree-Fock approximation, the low density stable phase (even in the absence of any interlayer tunneling) is a quantum ``pseudospin rotated'' spontaneous interlayer phase coherent spin-polarized symmetric state rather than the classical Ising-like charge-transfer phase. The U(1) symmetry of the double quantum well system is broken spontaneously at this low density quantum phase transition, and the layer density develops quantum fluctuations even in the absence of any interlayer tunneling. The phase diagram for the double quantum well system is calculated in the carrier density--layer separation space, and the possibility of experimentally observing various quantum phases is discussed. The situation in the presence of an external electric field is investigated in some detail using the spin-polarized-local-density-approximation-based self-consistent technique and good agreement with existing experimental results is obtained.
Ortalano M. W.
Sarma Sankar Das
Zheng Lian
No associations
LandOfFree
Exchange Instabilities in Semiconductor Double Quantum Well Systems does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Exchange Instabilities in Semiconductor Double Quantum Well Systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exchange Instabilities in Semiconductor Double Quantum Well Systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-177720