3,005 research outputs found
Compressibility of a 2D electron gas under microwave radiation
Microwave irradiation of a two-dimensional electron gas (2DEG) produces a
non-equilibrium distribution of electrons, and leads to oscillations in the
dissipative part of the conductivity. We show that the same non-equilibrium
electron distribution induces strong oscillations in the 2DEG compressibility
measured by local probes. Local measurements of the compressibility are
expected to provide information about the domain structure of the zero
resistance state of a 2DEG under microwave radiation.Comment: v2: analysis of the wave-vector dependence of the compressibility
added; discussion of the Hall conductivity removed (shifted to
cond-mat/0409590 in a revised form
Multiphoton antiresonance
We show that nonlinear response of a quantum oscillator displays antiresonant
dips and resonant peaks with varying frequency of the driving field. The effect
is a consequence of special symmetry and is related to resonant multiphoton
mixing of several pairs of oscillator states at a time. We discuss the
possibility to observe the antiresonance and the associated multiphoton Rabi
oscillations in Josephson junctions.Comment: 4 pages, 3 figures; corrected referenc
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