Visualizing broken symmetry and topological defects in a quantum Hall ferromagnet

X Liu, G Farahi, CL Chiu, Z Papic, K Watanabe… - Science, 2022 - science.org
The interaction between electrons in graphene under high magnetic fields drives the
formation of a rich set of quantum Hall ferromagnetic (QHFM) phases with broken spin or …

Broken symmetries and excitation spectra of interacting electrons in partially filled Landau levels

G Farahi, CL Chiu, X Liu, Z Papic, K Watanabe… - Nature Physics, 2023 - nature.com
Interacting electrons in flat bands give rise to a variety of quantum phases. One fundamental
aspect of such states is the ordering of the various flavours—such as spin or valley—that the …

Excitons in the fractional quantum Hall effect

NJ Zhang, RQ Nguyen, N Batra, X Liu, K Watanabe… - Nature, 2025 - nature.com
Excitons, Coulomb-driven bound states of electrons and holes, are typically composed of
integer charges,. However, in bilayer systems influenced by charge fractionalization,, a more …

Spin-valley entangled quantum Hall states in graphene

N Stefanidis, IS Villadiego - Physical Review B, 2023 - APS
We investigate interaction-driven integer quantum Hall states realized in Landau levels of
monolayer graphene when two out of its four nearly degenerate spin-valley flavors are filled …

Global phase diagram of charge-neutral graphene in the quantum Hall regime for generic interactions

SJ De, A Das, S Rao, RK Kaul, G Murthy - Physical Review B, 2023 - APS
Monolayer graphene at charge neutrality in a quantizing magnetic field is a quantum Hall
ferromagnet. Due to the spin and valley (near) degeneracies, there is a plethora of possible …

Magnonics: Materials, physics, and devices

X Han, H Wu, T Zhang - Applied Physics Letters, 2024 - pubs.aip.org
Magnon, the quanta of spin waves, can serve as an efficient spin information carrier for
memory and logic applications, with the advantages of the Joule-heating free induced low …

Fractional quantum Hall coexistence phases in higher Landau levels of graphene

J An, AC Balram, U Khanna, G Murthy - Physical Review B, 2025 - APS
Monolayer graphene under a strong magnetic field near charge neutrality manifests the
integer and fractional quantum Hall effects. Since only some of the four spin/valley flavors …

Landau-Level Mixing and Symmetry Breaking in Graphene

N Wei, G Xu, IS Villadiego, C Huang - Physical Review Letters, 2025 - APS
Recent scanning tunneling microscopy experiments on graphene at charge neutrality under
strong magnetic fields have uncovered a ground state characterized by Kekulé distortion …

Competing spin-valley entangled and broken symmetry states in the Landau level of graphene

N Stefanidis, IS Villadiego - Physical Review B, 2023 - APS
The nature of states in the quantum Hall regime of graphene in higher Landau levels
remains poorly understood partly because of the lack of a model that captures its valley …

Magnetic and lattice ordered fractional quantum Hall phases in graphene

J An, AC Balram, G Murthy - Physical Review B, 2024 - APS
At and near charge neutrality, monolayer graphene in a perpendicular magnetic field is a
quantum Hall ferromagnet. In addition to the highly symmetric Coulomb interaction, residual …