Correlated phases of excitons in semiconductor moir superlattices
Abstract
The problem of interacting quantum particles in a lattice is of central importance in condensed matter physics. Despite theoreticalpredictions of a host of remarkable quantum states of matter for interacting bosons in a lattice (such as the Mott insulators, superfluids, solids, and supersolids), experimental studies have so far been limited to bosonic atoms in an optical lattice and spin excitations in certain magnetic insulators. In this project, we propose to realize a new boson-in-a-lattice system for interlayer excitons (bound electron-hole pairs) in vertical heterostructures of semiconducting transition metal dichalcogenides (TMDs). Using this platform, we will explore the emergent quantum states and quantum phase transitions of excitons. The specific objectives include: (i)realization of the exciton-Mott insulating state; (ii)investigation of the Mott insulator-superfluid transition; and (iii) investigation of the exciton solid phases. Our approach is centered on trapping holes in a long-wavelength TMD moire superlattice and forming tightly bound interlayer excitons by Coulomb interaction between the trapped holes and electrons that reside in a closely spaced TMD monolayer. The project relies on a suit of device fabrication, optical characterization, and electrical transport and capacitancetechniques that are developed to address the TMD heterostructures specifically. Experimental realization of interacting excitons ina lattice is fundamentally important. It will allow us to explore the interacting boson physics in regimes not accessible by the cold-atom and the spin systems. It will also provide an opportunity to design new device concepts utilizing the quantum phases of bosons. In particular, the possibility of realizing high-temperature exciton superfluidity and superconductivity can impact the DOD capabilities in nanoscale computing and sensing devices, circuits and architectures.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 05, 2021
- Source ID
- N000142112471
Entities
People
- Kin Fai Mak
Organizations
- Cornell University
- Office of Naval Research
- United States Navy