Fig. 1: Experimental investigation of quench dynamics in a 2D electron system.
From: Screening the Coulomb interaction leads to a prethermal regime in two-dimensional bad conductors
a Schematic diagram of a Si MOSFET and the measurement set-up (Methods). Samples and the (metallic) measurement leads are mounted in vacuum. At low T < 2 K, the 2DES is connected to a thermal bath mainly through the measurement leads which are attached to the source and drain contacts. When the mean electron separation (a) is larger than the distance from the metallic gate (dox), the Coulomb interaction is modified from the long-range ~ 1/r to a screened or short-range ~ 1/r3 form. Total electron density ns is controlled by the gate voltage Vg. b Vg and T vs time (t) in a typical experimental protocol. Nonequilibrium dynamics is launched at t = 0 by a rapid change of ns from its initial to a final state value. c Conductivity σ(t) corresponding to the protocol in b in the short-range case (sample 2 × 20): \({V}_{{{{{{{{\rm{g}}}}}}}}}^{{{{{{{{\rm{i}}}}}}}}}=2.5\) V [\({n}_{{{{{{{{\rm{s}}}}}}}}}^{{{{{{{{\rm{i}}}}}}}}}(1{0}^{11}{{{{{{{{\rm{cm}}}}}}}}}^{-2})=32.2\)], \({V}_{{{{{{{{\rm{g}}}}}}}}}^{{{{{{{{\rm{f}}}}}}}}}=1.74\) V [\({n}_{{{{{{{{\rm{s}}}}}}}}}^{{{{{{{{\rm{f}}}}}}}}}(1{0}^{11}{{{{{{{{\rm{cm}}}}}}}}}^{-2})=8.44 > {n}_{{{{{{{{\rm{c}}}}}}}}}\)]; T = 0.92 K. Inset: Expanded view of the relaxation after ns change. Red dashed line indicates the (time-averaged) equilibrium conductivity in the final state, \({\sigma }_{0}({n}_{{{{{{{{\rm{s}}}}}}}}}^{{{{{{{{\rm{f}}}}}}}}},T)\). Source data are provided as a Source Data file.
