Absence of heat flow in ν = 0 quantum Hall ferromagnet in bilayer graphene

Abstract

The charge neutrality point of bilayer graphene, denoted as ν = 0 state, manifests competing phases marked by spontaneously broken isospin (spin/valley/layer) symmetries under external magnetic and electric fields. However, due to their electrically insulating nature, identifying these phases through electrical conductance measurements remains challenging. A recent theoretical proposal introduces a novel approach, employing thermal transport measurements to detect these competing phases. Here, we experimentally explore the bulk thermal transport of the ν = 0 state in bilayer graphene to investigate its ground states and collective excitations associated with isospin. While the theory anticipates a finite thermal conductance in the ν = 0 state, our findings unveil an absence of detectable thermal conductance. Through variations in the external electric field and temperature-dependent measurements, our results suggest towards gapped collective excitations at ν = 0 state. Our findings underscore the necessity for further investigations into the nature of ν = 0.

References in corpus (21)

• Quantum Hall Ferromagnetism in Graphene
• The zero-energy state in graphene in a high magnetic field
• Quantum limit of heat flow across a single electronic channel
• Dissipative Quantum Hall Effect in Graphene near the Dirac Point
• Graphene integer quantum Hall effect in the ferromagnetic and paramagnetic regimes
• Evidence for a Spin Phase Transition at ν=0 in Bilayer Graphene
• Local Compressibility Measurements of Correlated States in Suspended Bilayer Graphene
• Visualizing Broken Symmetry and Topological Defects in a Quantum Hall Ferromagnet
• Imaging tunable quantum Hall broken-symmetry orders in graphene
• The Effects of Landau level mixing on the fractional quantum Hall effect in monolayer Graphene
• Vanishing thermal equilibration for hole-conjugate fractional quantum Hall states in graphene
• SO(5) symmetry in the quantum Hall effect in graphene
• Observation of ballistic upstream modes at fractional quantum Hall edges of graphene
• Determination of topological edge quantum numbers of fractional quantum Hall phases
• Heat equilibration of integer and fractional quantum Hall edge modes in graphene
• Metallic Phase and Temperature Dependence of the $\nu =0$ Quantum Hall State in Bilayer Graphene
• SU(4) spin waves in the $\nu =\pm 1$ quantum Hall ferromagnet in graphene
• Theory of Competing Charge Density Wave, Kekule and Antiferromagnetic ordered Fractional Quantum Hall states in Graphene aligned with Boron Nitride
• Phase diagram of the $\nu =2$ quantum Hall state in bilayer graphene
• Vanishing bulk heat flow in the nu=0 quantum Hall ferromagnet in monolayer graphene
• Electrical noise spectroscopy of magnons in a quantum Hall ferromagnet

Cited by in corpus (4)

• Vanishing bulk heat flow in the nu=0 quantum Hall ferromagnet in monolayer graphene
• Half-integer thermal conductance in the absence of Majorana mode
• Anomalous Transport Gaps of Fractional Quantum Hall Phases in Graphene Landau Levels are Induced by Spin-Valley Entangled Ground States
• Uniquely identifying quantum Hall phases in charge neutral graphene