Evidence for a finite compressibility of a quasi-one-dimensional ballistic channel

It is known that the local conditions in an electrical circuit can affect a nearby, but electrically isolated circuit. Such a ‘noninvasive’ measurement technique can be employed to study the screening ability (compressibility) of an electron system. In this work, we use a quasione-dimensional ballistic channel to screen an electric field between a gate and lateral quantum dot. Our results clearly show that the screening ability decreases with decreasing number of occupied 1D channel. When there are a large number of 1D subbands occupied in the channel, the screening ability tends to saturate, approaching its 2D limit. q 2005 Elsevier Ltd. All rights reserved.