Related papers: Chiral Quantum Phases and Tricriticality in a Dick…
The interplay of interactions, symmetries and gauge fields usually leads to intriguing quantum many-body phases. To explore the nature of emerging phases, we study a quantum Rabi triangle system as an elementary building block for…
Quantum tricriticality, a unique form of high-order criticality, is expected to exhibit fascinating features including unconventional critical exponents and universal scaling laws. However, a quantum tricritical point (QTCP) is much harder…
I first sketch recent developments concerning the phase diagram of strongly interacting matter as a function of temperature and baryon density, obtained using a model for two-flavor QCD in which the interaction between quarks is modelled on…
The quantum tricriticality of d-dimensional transverse Ising-like systems is studied by means of a perturbative renormalization group approach focusing on static susceptibility. This allows us to obtain the phase diagram for 3<d<4, with a…
The disordered quantum world hosts three fundamental types of states: extended, localized, and critical, of which the critical states are confined to fine-tuned critical points or mobility edges in randomly disordered systems. The…
Superradiant phase transitions play a fundamental role in understanding the mechanism of collective light-matter interaction at the quantum level. Here we investigate multiple superradiant phases and phase transitions with different…
The Dicke model (DM) serves as a paradigm for understanding collective light-matter interactions. We introduce the chiral Dicke model, a generalization where an atomic ensemble couples to a two-mode cavity via chiral interactions. Unlike…
Quantum phase transitions with multicritical points are fascinating phenomena occurring in interacting quantum many-body systems. However, multicritical points predicted by theory have been rarely verified experimentally; finding…
The interplay of interaction and dissipation in open quantum systems can forge phase transitions beyond conventional paradigms. In the canonical quantum Rabi model, we demonstrate that a photon-photon (Kerr) interaction transforms the…
We describe the quantum phase transitions in the ferromagnetic Dicke-Ising model using a Landau theory approach. The theory quantitatively captures the change from a second- to a first-order transition between the normal and superradiant…
A generic two-dimensional disordered topological superconductor in symmetry class D exhibits rich phenomenology and multiple phases: diffusive thermal metal (DTM), Anderson insulator (AI), and thermal quantum Hall (TQH) phase (a topological…
We investigate dissipative phase transitions (DPTs) in a parametrically amplified open quantum Rabi model (QRM) with both single- and two-photon decay. In the classical oscillator limit, four composite phases emerge, arising from the…
Quantum critical points (QCPs) emerge when a 2nd order phase transition is suppressed to zero temperature. In metals the quantum fluctuations at such a QCP can give rise to new phases including unconventional superconductivity. Whereas…
We demonstrate the emergence of nonreciprocal superradiant phase transitions and novel multicriticality in a cavity quantum electrodynamics (QED) system, where a two-level atom interacts with two counter-propagating modes of a…
We present a theory describing the superconducting (SC) interaction of Dirac electrons in a quasi-two-dimensional system consisting of a stack of N planes. The occurrence of a SC phase is investigated both at T=0 and T\neq 0, in the case of…
Recently, the quantum contact process, in which branching and coagulation processes occur both coherently and incoherently, was theoretically and experimentally investigated in driven open quantum spin systems. In the semi-classical…
The quark number susceptibility near the QCD critical end-point (CEP), the tricritical point (TCP) and the O(4) critical line at finite temperature and quark chemical potential is investigated. Based on the universality argument and…
We present exotic quantum phases in a quantum Rabi hexagonal ring, which is derived by an analytical solution. We find that an artificial magnetic field applied in the ring induces an effect magnetic flux in the even and odd subring. It…
Within the proper-time renormalization group approach, the chiral phase diagram of a two-flavor quark-meson model is studied. In the chiral limit, the location of the tricritical point which is linked to a Gaussian fixed point, is…
The chiral phase transition at finite temperature T and/or chemical potential $\mu$ is studied using the QCD-like theory with a variational approach. The ``QCD-like theory'' means the improved ladder approximation with an infrared cutoff in…