Details

Autor(en) / Beteiligte

• Geraedts, Scott D.
• Zaletel, Michael P.
• Mong, Roger S. K.
• Metlitski, Max A.
• Vishwanath, Ashvin
• Motrunich, Olexei I.

Titel

The half-filled Landau level: The case for Dirac composite fermions

Ist Teil von

• Science (American Association for the Advancement of Science), 2016-04, Vol.352 (6282), p.197-201

Ort / Verlag

United States: American Association for the Advancement of Science

Erscheinungsjahr

2016

Link zum Volltext

Quelle

American Association for the Advancement of Science

Beschreibungen/Notizen

• In a two-dimensional electron gas under a strong magnetic field, correlations generate emergent excitations distinct from electrons. It has been predicted that "composite fermions"—bound states of an electron with two magnetic flux quanta—can experience zero net magnetic field and form a Fermi sea. Using infinite-cylinder density matrix renormalization group numerical simulations, we verify the existence of this exotic Fermi sea, but find that the phase exhibits particle-hole symmetry. This is self-consistent only if composite fermions are massless Dirac particles, similar to the surface of a topological insulator. Exploiting this analogy, we observe the suppression of 2kF backscattering, a characteristic of Dirac particles. Thus, the phenomenology of Dirac fermions is also relevant to two-dimensional electron gases in the quantum Hall regime.