Field-enhanced conductivity in Electron-GlassesSuppression of Electron-Electron inelastic scattering in Anderson Insulators

disorderAnderson insulator…

= Electron-Glass

… Coulomb interactions

x

x

G(T=0)>0Metal

G(T=0)=0Insulator

The basic phenomena

…quench the sample from high T…

all samples are in the 2D hopping regime…and all are crystalline indium-oxide - In2O3-x

…all experiments done at T=4K

…slow relaxation…system goes towards lower energy

In2O3-x

…more ways to get it out of equilibrium...

…apply non-ohmic field F…(high voltage)

…or raise bath-temperature by T…

…F and T have qualitatively similar effect …

… absorption measured via transport...

… absorption however, DOES depend on f...

… and it becomes small above some f...

G0

G0 is the same for all f

Grel is NOT…what determines the cross-over frequency ?

…and F is kept for the same time for all f

)())(()(

2

TTTCVR

Vel

(T) is the rate heat is removed from the system

Cel is the electron heat-capacity

TkNTC Bel22 )0(

3

2)(

T, T

…it is the rate of heat removal…

(6.1 M) =3.5·105 Hz (12.5 M) =7.1·105 Hz

N(0)=21045 J-1 m-3

V(6.1 M) =0.3 V (rms)

V(12.5 M) =1 V (rms)

…but what about e-e inelastic rate ?!

K101 4 00)0(

12

dN

in (e-e)R (for weak disorder)

0T

…MD shape may be used as a thermometer...

gate

insulator

sample

…the “memory-Dip (MD )

…measuring the electron temperature…

…applied high frequency F... …applied low frequency F...