Triple-top-gate technique for studying the strongly interacting 2D electron systems in heterostructures

Abstract

We have developed a technique that dramatically reduces the contact resistances and depletes a shunting channel between the contacts outside the Hall bar in ultra-high mobility SiGe/Si/SiGe heterostructures. It involves the creation of three overlapping independent gates deposited on top of the structure and allows transport measurements to be performed at millikelvin temperatures in the strongly interacting limit at low electron densities, where the energy of the electron-electron interactions dominates all other energy scales. This design allows one to observe the two-threshold voltage-current characteristics that are a signature for the collective depinning and sliding of the electron solid.

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Cited by in corpus (3)

• Stabilization of a two-dimensional quantum electron solid in perpendicular magnetic fields
• Inequivalence of the low-density insulating state and quantum Hall insulating states in a strongly correlated two-dimensional electron system
• Quantum Wigner solid in two-dimensional electron systems in semiconductors