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Tunneling signatures of interband coherence in dilute exciton condensates

Kryštof Kolář1,2 and Felix von Oppen3

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Phys. Rev. B 114, 125128 – Published 24 August, 2026

DOI: https://doi.org/10.1103/mb3n-l45p

Abstract

We theoretically investigate signatures of exciton condensation and the underlying interband coherence in scanning tunneling microscopy. We consider both monolayer and bilayer condensates in the regime of a dilute condensate of tightly bound excitons. For monolayer condensates, interband coherence is directly encoded in spatially oscillating contributions to the tunneling conductance, which break the underlying lattice symmetry. We show how scanning tunneling microscopy allows one to extract the exciton wave function. For bilayer condensates, we show that the formation of the exciton insulator is signaled by the emergence of a characteristic peak in the tunneling conductance, which can be used to extract the (local) exciton density. Our results are based on analytical considerations using a systematic solution of the mean-field equations in powers of the exciton density as well as numerical calculations.

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Phys. Rev. B 114, 125128– Published 24 August, 2026
  • Received 12 February 2026
  • Revised 22 May 2026
  • Accepted 10 August 2026
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