Commensurate-incommensurate transitions of quantum Hall stripe states in double quantum well systems

Article

关键词: SPONTANEOUS INTERLAYER COHERENCE;    2-DIMENSIONAL ELECTRON-SYSTEMS;    TILTED MAGNETIC-FIELDS;    HIGH LANDAU-LEVELS;    PHASE-TRANSITIONS;    COLLECTIVE MODES;    ANISOTROPIC TRANSPORT;    WIGNER CRYSTAL;    FERROMAGNETS;   

DOI  :  10.1103/PhysRevB.66.205315

来源: SCIE

【 摘 要 】

In higher Landau levels (N>0) and around filling factors nu=4N+1, a two-dimensional electron gas in a double quantum well system supports a stripe ground state in which the electron density in each well is spatially modulated. When a parallel magnetic field is added in the plane of the wells, tunneling between the wells acts as a spatially rotating effective Zeeman field coupled to the pseudospins describing the well index of the electron states. For small parallel fields, these pseudospins follow this rotation, but at larger fields they do not, and a commensurate-incommensurate transition results. Working in the Hartree-Fock approximation, we show that the combination of stripes and commensuration in this system leads to a very rich phase diagram. The parallel magnetic field is responsible for oscillations in the tunneling matrix element that induce a complex sequence of transitions between commensurate and incommensurate liquid or stripe states. The homogeneous and stripe states we find can be distinguished by their collective excitations and tunneling I-V, which we compute within the time-dependent Hartree-Fock approximation.

【 授权许可】

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