Quantum Transport in 2D Semiconductors

Technical Report · Fri Dec 15 04:00:00 EST 2023

DOI:https://doi.org/10.2172/2204858· OSTI ID:2204858

Hone, James ^[1]; Dean, Cory ^[2]

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1. Columbia Univ., New York, NY (United States); Columbia University
2. Columbia Univ., New York, NY (United States)

Leveraging progress in synthesis of ultra-pure transition metal dichalcogenide (TMD) crystals, our team has made key breakthroughs in the study of quantum states in two-dimensional (2D) TMD semiconductors. Using a capacitance spectroscopy technique, we have observed the first signatures of fractional quantum Hall states in monolayer WSe₂ and clear signatures of interlayer exciton condensates in bilayer WSe₂. In a transport study of bilayer WSe₂, we report observation of spin-selective magneto-conductivity in WSe₂. To improve electrical transport studies, we have focused on metal-TMD contacts by studying the behavior of metal-TMD contacts in the clean limit, and developing a new contact doping technique that achieves Ohmic contact down to low temperature and low carrier density. Using this new technique, we study electrical transport in monolayer WSe₂ down to low temperature and low carrier density, finding record-high hole mobility and evidence of a metal-insulator transition at low density. Under high magnetic fields, we observe clear signatures of fractional quantum Hall effect in transport for the first time in a TMD.

• Research Organization: Columbia Univ., New York, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
• DOE Contract Number: SC0016703
• OSTI ID: 2204858
• Report Number(s): DOE-COLUMBIA--16703
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY