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Heat conductance of the quantum Hall bulk
Ron Aharon Melcer1,2, Avigail Gil2, Arup Kumar Paul1,2
1Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot, Israel.
Nature
|January 3, 2024
Summary
Localized states in the quantum Hall effect bulk conduct heat efficiently, even when the material is electrically insulating. This study reveals their crucial role in thermal transport, offering new insights into topological matter.
Area of Science:
- Condensed Matter Physics
- Topological Matter
- Quantum Hall Effect
Background:
- The quantum Hall effect (QHE) is a key example of topological states of matter, arising from complex interactions and disorder.
- Disorder creates localized states in the bulk, crucial for stabilizing QHE states but difficult to study experimentally.
- Understanding the transport properties of these localized states is essential for advancing topological physics.
Purpose of the Study:
- To investigate the thermal transport properties of localized states in the bulk of quantum Hall systems.
- To experimentally separate bulk thermal conductance from edge contributions in a microfabricated device.
- To elucidate the role of localized states in heat conduction within topological insulators.
Main Methods:
- Utilized a novel 'multiterminal' short device with a 10 µm scale for precise measurements.
- Separated longitudinal thermal conductance (bulk contribution) from transverse thermal conductance (edge contribution).
- Analyzed heat conductance variations with magnetic field tuning, particularly away from conductance plateau centers.
Main Results:
- Demonstrated that localized states in the bulk conduct heat efficiently ([Formula: see text]) while the bulk remains electrically insulating.
- Observed finite heat conductance ([Formula: see text]) across plateaus for fractional states (e.g., [Formula: see text], [Formula: see text]) in the first excited Landau level.
- Showcased efficient heat conduction through localized states when the magnetic field is tuned away from the plateau center.
Conclusions:
- Localized states in the quantum Hall effect bulk are efficient heat conductors.
- The study provides experimental evidence for the significant role of bulk localized states in thermal transport.
- A theoretical model supports the findings, identifying localized states as the origin of finite heat conductance.
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