Trion gas, electron-hole liquid, and metal-insulator transition in doped heterostructures based on transition metal dichalcogenides

TL;DR

This paper investigates how doping influences the phase behavior, transition mechanisms, and metal-insulator transition of electron-hole liquids in transition metal dichalcogenide heterostructures, providing a detailed phase diagram and analysis.

Contribution

It introduces a comprehensive phase diagram for electron-hole liquids in doped TMD heterostructures and analyzes doping effects on phase transitions and metal-insulator behavior.

Findings

Doping with more valleys favors high-temperature EHL formation.

Transition from trion gas to electron-hole plasma is characterized by a modified Mott criterion.

Doping significantly affects the metal-insulator transition in equilibrium conditions.

Abstract

The effect of doping on the parameters of an electron-hole liquid (EHL) in heterostructures based on transition metal dichalcogenides is studied. The phase diagram of the EHL is constructed. It is shown that for the formation of a high-temperature tightly bound EHL, as well as for the transition from the semiconducting (exciton) state to the semimetallic one (electron-hole plasma/liquid), it is advantageous to dope the energy band with larger number of valleys. The transition from trion gas to electron-hole plasma is investigated using the modified Mott criterion and variational calculation with screened potential. The effect of doping on the metal--insulator transition in the equilibrium case without laser excitation is studied.