Detailseite
Projekt
Quantum criticality: coupled renormalization of electrons and order parameter fluctuations
Antragsteller
Professor Dr. Walter Metzner
Fachliche Zuordnung
Theoretische Physik der kondensierten Materie
Förderung
Förderung von 2007 bis 2015
Projektkennung
Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 21278441
In this project we study several types of quantum phase transitions in interacting Fermi systems, between a symmetric phase and an ordered phase with spontaneously broken symmetry. These include the nematic transition in metals, a normal to superfluid transition in semi-metals, and chiral symmetry breaking in the (relativistic) Thirring model. The main focus will be on (2+1)-dimensional systems. We are particularly interested in systems for which an effective order parameter theory truncated at quartic order in the fields (Hertz-Millis theory) does not describe the low energy behavior correctly. The functional RG will be used to analyze the coupled system of electronic excitations and order parameter fluctuations, that is, fermions and bosons will be integrated out simultaneously. We will try to derive and solve a set of flow equations which properly treats all the entangled singularities appearing near the quantum phase transition. We will access all regions of the phase diagram, including the symmetry-broken regime and regimes governed by non-Gaussian fluctuations. We will take full advantage of the possibilities of the functional RG by allowing also for truly functional flows, such as flows of the fullo rder parameter potential, capturing vertices with arbitrary powers of the fields.
DFG-Verfahren
Forschungsgruppen
Beteiligte Person
Professor Dr. Holger Gies
