Heterobilayers of 2D materials as a platform for excitonic superfluidity

Abstract

Excitonic condensate has been long-sought within bulk indirect-gap semiconductors, quantum wells, and 2D material layers, all tried as carrying media. Here we propose intrinsically stable 2D semiconductor heterostructures with doubly-indirect overlapping bands as optimal platforms for excitonic condensation. After screening hundreds of 2D materials, we identify candidates where spontaneous excitonic condensation mediated by purely electronic interaction should occur, and hetero-pairs Sb2Te2Se/BiTeCl, Hf2N2I2/Zr2N2Cl2, and LiAlTe2/BiTeI emerge promising. Unlike monolayers, where excitonic condensation is hampered by Peierls instability, or other bilayers, where doping by applied voltage is required, rendering them essentially non-equilibrium systems, the chemically-specific heterostructures predicted here are lattice-matched, show no detrimental electronic instability, and display broken type-III gap, thus offering optimal carrier density without any gate voltages, in true-equilibrium. Predicted materials can be used to access different parts of electron-hole phase diagram, including BEC-BCS crossover, enabling tantalizing applications in superfluid transport, Josephson-like tunneling, and dissipationless charge counterflow.

arXiv comment4 figure

References in corpus (29)

• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Landau level degeneracy and quantum Hall effect in a graphite bilayer
• Two-dimensional materials from high-throughput computational exfoliation of experimentally known compounds
• Evidence of high-temperature exciton condensation in 2D atomic double layers
• High-temperature superfluidity with indirect excitons in van der Waals heterostructures
• Signatures of exciton condensation in a transition metal dichalcogenide
• Chiral skyrmions in thin magnetic films: new objects for magnetic storage technologies?
• Room-Temperature Superfluidity in Graphene Bilayers
• Exciton condensate in semiconductor quantum well structures.
• Counterflow measurements in strongly correlated GaAs hole bilayers: evidence for electron-hole pairing
• Excitonic superfluid phase in Double Bilayer Graphene
• Quantum Hall Drag of Exciton Superfluid in Graphene
• Quantum Monte Carlo Calculation of the Binding Energy of Bilayer Graphene
• High Temperature Superfluidity in Double Bilayer Graphene
• Excitonic condensation in a symmetric electron-hole bilayer
• Macroscopic quantum computation using Bose-Einstein condensates
• Electron screening and excitonic condensation in double-layer graphene systems
• Strongly enhanced tunneling at total charge neutrality in double bilayer graphene-WSe${}_2$ heterostructures
• Theory of Two-Dimensional Spatially Indirect Equilibrium Exciton Condensates
• Many-body and spin-orbit effects on direct-indirect band gap transition of strained monolayer MoS${}_2$ and WS${}_2$
• Quantum Walk in Momentum Space with a Bose-Einstein Condensate
• Cooper pairing of electrons and holes in graphene bilayer: Correlation effects
• Electronic and vibrational properties of ${\text{TiSe}}_2$ in the charge-density wave phase from first principles
• Critical role of the exchange interaction for the electronic structure and charge-density-wave formation in TiSe2
• Exciton condensate in bilayer transition metal dichalcogenides: strong coupling regime
• Reproduction of the charge density wave phase diagram in $1T$-${\mathrm{TiSe}}_2$ exposes its excitonic character
• Fate of the excitonic insulator in the presence of phonons
• Excitonic effects in two-dimensional TiSe${}_2$ from hybrid density functional theory
• Space charge and screening in bilayer graphene

Cited by in corpus (12)

• Quantum Metric and Correlated States in Two-dimensional Systems
• Nanotube-based one-dimensional heterostructures coupled by van der Waals forces
• Parity-Dependent Moiré Superlattices in Graphene/h-BN Heterostructures: A Route to Mechanomutable Metamaterials
• Realizing Topological Superconductivity in Tunable Bose-Fermi Mixtures with Transition Metal Dichalcogenide Heterostructures
• Beginnings of Exciton Condensation in Coronene Analog of Graphene Double Layer
• Plasmonic photonic crystal mirror for long-lived interlayer exciton generation
• Excitonic insulators and Gross-Neveu models
• Exciton energy spectra in polyyne chains
• Excitonic insulators and superfluidity in 2D bilayers without external fields
• Collective modes and Raman response in Ta${}_2$NiSe${}_5$
• Interface engineering of van der Waals heterostructures towards energy-efficient quantum devices operating at high temperatures
• Tunable electronic energy level alignment and exciton diversity in organic-inorganic van der Waals heterostructures