Comment on cond-mat0409228 Microwave photoresponse in the 2D(3)

We provide an article-extract which points out that a microwave-induced modification in the resistance occurs at relatively "high" magnetic fields where the radiation is incapable of producing inter-Landau level excitations and, therefore, that the microwa

ARTICLE4

R.G.Mani/PhysicaE

Rxx( )

0.00.00.00.04/5 Bf

B (T)

Fig.4.This gureshowsthedevelopmentoftheradiationinducedzero-resistancestateswiththeelectromagneticwavefrequency,f;overanintermediatef-range,whereazero-resistancestateoccursabout4Bf:NotethattheminimaareshiftedtoprogressivelyhigherBwithincreasingf:

isincreasedfrom9.79–15:6GHz;theRxx

decreasebelowthedarkRxxbecomesprogressivelyweaker,asapeakintheRxxdevelopswithincreasingf:AlthoughapluralityofoscillationsarenotevidentinRxxat15:6GHz;itisclearthat,at15:6GHz;BfcoincideswithneitheraminimumnoramaximuminRxx;asinthehigherfdatatobeexhibitedinFig.4.

Withafurtherincreaseinf;anumberofradiation-inducedoscillationsbecomeself-evidentinRxx;asshowninFig.4.Here,largeamplitudeoscillationsthatscalewithfoccurbelow0:3T;andtheseareattributedtotheradiation-inducedmagneto-resistanceeffect,whiletheweakresis-tanceoscillationsbetween0:3pBp0:4TareassociatedwiththeShubnikov–deHaaseffect.Thenoteworthyfeaturehereisthemanifestationofazero-resistancestateabout4Bf;whichshiftstoprogressivelyhigherB;withincreasingf: