Geometric Stiffness in Interlayer Exciton Condensates

Abstract

Recent experiments have confirmed the presence of interlayer excitons in the ground state of transition metal dichalcogenide (TMD) bilayers. The interlayer excitons are expected to show remarkable transport properties when they undergo Bose condensation. In this work, we demonstrate that quantum geometry of Bloch wavefunctions plays an important role in the phase stiffness of the Interlayer Exciton Condensate (IEC). Notably, we identify a geometric contribution that amplifies the stiffness, leading to the formation of a robust condensate with an increased BKT temperature. Our results have direct implications for the ongoing experimental efforts on interlayer excitons in materials that have non-trivial quantum geometry. We provide quantitative estimates for the geometric contribution in TMD bilayers through a realistic continuum model with gated Coulomb interaction, and find that the substantially increased stiffness allows for an IEC to be realized at amenable experimental conditions.

improved presentation

References in corpus (10)

• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
• Evidence of high-temperature exciton condensation in 2D atomic double layers
• High-temperature superfluidity with indirect excitons in van der Waals heterostructures
• Band geometry, Berry curvature and superfluid weight
• Essay: Where Can Quantum Geometry Lead Us?
• Effective theory and emergent $SU(2)$ symmetry in the flat bands of attractive Hubbard models
• Berry Phase Effect on Exciton Transport and Bose Einstein Condensate
• Exciton condensate in bilayer transition metal dichalcogenides: strong coupling regime
• Wigner supersolid of excitons in electron-hole bilayers
• Superconductivity-induced spectral weight transfer due to quantum geometry

Cited by in corpus (15)

• Theory of topological exciton insulators and condensates in flat Chern bands
• "Quantum Geometric Nesting" and Solvable Model Flat-Band Systems
• Instantaneous response and quantum geometry of insulators
• Quantum Metric in Step Response
• Quantum Geometry Probed by Chiral Excitonic Optical Response of Chern Insulators
• Corner Charge Fluctuation as an Observable for Quantum Geometry and Entanglement in Two-dimensional Insulators
• Quantum Geometry and the Hidden Scales in Materials
• Coherence length and quantum geometry in a dilute flat-band superconductor
• Pair size and quantum geometry in a multiband Hubbard model
• Many-Body Quantum Geometric Dipole
• Quantum-geometric dipole: a topological boost to flavor ferromagnetism in flat bands
• Superfluid stiffness bounds in time-reversal symmetric superconductors
• Quantum metric driven transition between superfluid and incoherent fluid
• Quantum Geometry Driven Finite-Momentum Exciton Fluctuations in Flat-Band Systems
• Third-harmonic generation in superconductors: Role of quantum geometry in the competition between Higgs mode and quasiparticles