Abstract
We report on our studies of magnetic breakdown (MB) in coupled GaAs/Al0.3 Ga0.7As double quantum wells (DQWs) subject to crossed magnetic fields. MB is a failure of semiclassical theory that occurs when a magnetic field causes electrons to tunnel across a gap in k-space from one Fermi surface (FS) branch to another. We study MB in a two-branch FS created by subjecting a DQW to an in-plane magnetic field (B∥). The principal effect of B∥ is a distortion in the dispersion curve of the system, yielding a FS consisting of two components, a lens-shaped inner orbit and an hour-glass-shaped outer orbit. The perpendicular field (B⊥) causes Landau level formation and Shubnikov-de Haas (SdH) oscillations for each branch of the FS. At higher perpendicular fields MB occurs and electrons tunnel through k-space from one FS orbit to the other. MB is observed by noting which peaks are present in the Fourier power spectrum of the magnetoresistance versus 1/B⊥ at constant B∥. We observe MB in two DQW samples over a range of B∥.
Original language | English (US) |
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Pages (from-to) | 595-600 |
Number of pages | 6 |
Journal | Superlattices and Microstructures |
Volume | 20 |
Issue number | 4 |
DOIs | |
State | Published - 1996 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Materials Science
- Condensed Matter Physics
- Electrical and Electronic Engineering