Nested Fermi surfaces and correlated electronic phases in hole-doped semiconductor quantum wells

TL;DR

This paper reveals how changing hole density in p-type semiconductor quantum wells causes Fermi surface nesting, leading to competing superconducting and density wave phases, which can be controlled via gating and magnetic fields.

Contribution

It demonstrates the emergence of nested Fermi surfaces and correlated phases in hole-doped quantum wells, a novel platform for tunable electronic order.

Findings

Nested Fermi surfaces occur at a critical hole density.

Nesting induces competing superconducting and density wave orders.

Correlated phases can be controlled by doping, gating, and magnetic fields.

Abstract

We demonstrate the existence of novel interaction effects in hole-doped semiconductor quantum wells which are connected to dramatic changes in the Fermi surface geometry occurring upon variation of the doping. We present band structure calculations showing that quantum wells formed in $p$-type cubic semiconductors develop nested Fermi surfaces at a critical hole density set by the width $d$ of the quantum well $k_F\sim \pi/d$. Nesting gives rise to competing superconducting and charge or spin density wave order, which we analyze using the perturbative renormalization group method. The correlated phases may be created or destroyed by tuning the hole density towards or away from the critical density. Our results establish $p$-type semiconductor quantum wells as a platform for novel correlated phases, which may be precisely controlled using electrostatic gating and external magnetic fields.