Microwave-induced Hall resistance in bilayer electron systems

Abstract

The influence of microwave irradiation on dissipative and Hall resistance in high-quality bilayer electron systems is investigated experimentally. We observe a deviation from odd symmetry under magnetic-field reversal in the microwave-induced Hall resistance R xy , whereas the dissipative resistance R xx obeys even symmetry. Studies of R xy as a function of the microwave electric field and polarization exhibit a strong and nontrivial power and polarization dependence. The obtained results are discussed in connection to existing theoretical models of microwave-induced photoconductivity.

Theory of magnetothermoelectric phenomena in high-mobility two-dimensional electron systems under microwave irradiation

“…6−11 According to both experiment and theory, the MW irradiation strongly affects the longitudinal (dissipative) resistivity and has a much weaker effect on the transverse (Hall) resistivity. More recent experiments uncover the existence of small corrections, sensitive to the direction of electric field of microwaves (MW polar-ization), to both longitudinal and Hall resistivities, 12,13 also in general agreement with the theory.…”

“…with the accuracy up to the linear terms in MW power, only the contributions with low-order, |n| ≤ 1, Bessel functions J n are to be taken in Eqs. (11) and (12). Physically, this corresponds to a neglect of multi-photon absorption processes.…”

“…In particular, the longitudinal thermopower in classically strong magnetic fields is written simply as α xx = ρ xy β yx . The influence of microwaves on Hall resistivity ρ xy is weak 12 , so α xx is directly determined by β yx . Neglecting the contributions of higher order in ν tr /ω c in Eqs.…”

Observation of microwave induced resistance and photovoltage oscillations in MgZnO/ZnO heterostructures

“…The prefactor A depends on the incident microwave power and becomes B independent for 1 in both theory and experiment. The Hall resistance R xy = B/en, where n is the electron areal density, remains classical and unaffected by the radiation in the range of B where MIROs have been observed so far [16][17][18][19], apart from changes that are in absolute terms comparable in size to the changes in the longitudinal resistivity. The microwave radiation does not only induce resistance oscillations periodic in the inverse of the magnetic field, but also generates photovoltage or photocurrent oscillations [20,21] with the same periodicity in samples with internal contacts due to * j.smet@fkf.mpg.de intrinsic internal electric fields associated with sample disorder and density inhomogeneities, for instance, near contacts [22].…”

Magneto-transport characteristics of a 2D electron system driven to negative magneto-conductivity by microwave photoexcitation

“…This property has been utilized to understand the experimental observation of the microwave-radiation-induced zero-resistance states in the GaAs/AlGaAs system 1 2 . Yet, the negative conductivity/resistivity state remains an enigmatic and open topic for investigation, although, over the past decade, photo-excited transport has been the subject of a broad and intense experimental 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 and theoretical 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 study in the 2D electron system (2DES).…”