Universität zu Köln

Ihrig, Bernhard Maurice Daniel Rolf (2021). Deconfined Quantum Critical Behavior of Dirac Materials. PhD thesis, Universität zu Köln.

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Abstract

This thesis investigates the quantum field theoretical description of Dirac system at (deconfined) quantum critical points ([D]QCP). Using the perturbative renormalization group (RG) in higher loop orders, the critical behavior is quantitatively analyzed. In the first project, a detailed resummation of the four loop RG of the Gross-Neveu-Yukawa model is laid out for this matter. While the Landau-Ginzburg-Wilson paradigm used for this purpose proves to be very successful, exotic phase transitions beyond are treated in the remaining parts of this work. The studied quantum phase transitions describe an unexpected order-to-order transition and unveil a web of novel dualities between different theories. The second project examines the critical theory of a DQCP to the fourth loop order to address the question of transition's nature. The third project checks one of the new dualities for a system of gauged Dirac fermions. In the fourth and final project, the critical theory of a DQCP composed by fractionalized degrees of freedom is analyzed quantitatively using a series of complementary RG methods.

Item Type:	Thesis (PhD thesis)
Creators:	Creators Email ORCID ORCID Put Code Ihrig, Bernhard Maurice Daniel Rolf bernhard.ihrig@gmx.de UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-530777
Date:	27 January 2021
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Physics > Institute for Nuclear Physics
Subjects:	Physics
Uncontrolled Keywords:	Keywords Language Quantum Field Theory English Quantum Phase Transition English Renormalization Group English Dirac Materials English Deconfined Criticality English
Date of oral exam:	26 April 2021
Referee:	Name Academic Title Scherer, Michael PD Dr. Trebst, Simon Prof. Dr.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/53077