Michal Rokni and Premala Chandra Chandra Tech Consulting LLC, 123 Harper Street, Highland Park, NJ 08904 Abstract We present a dynamical study of the disordered quantum p = 2 spherical model at long times. Its phase behavior as a function of spin-bath coupling, strength of quantum fluctuations and temperature is characterized, and we identify different paramagnetic and coarsened regions. A quan...

We try to use scale-invariance and the large-N limit to construct a non-trivial 4d O(N) scalar field model with good UV behavior and naturally light scalar excitations. The physical principle is to fix the interactions (not assumed polynomial) at each order in 1/N by requiring the effective action for arbitrary background fields to be scale-invariant, after including quantum effects. We find a ...

This article briefly reviews three topics related to the quantum critical behavior of certain heavy-fermion systems. First, we summarize an extended dynamical mean-field theory for the Kondo lattice, which treats on an equal footing the quantum fluctuations associated with the Kondo and RKKY couplings. The resulting dynamical mean-field equations describe a Kondo impurity model with an addition...

We study a ($1+1$)-dimensional quantum circuit consisting of Haar-random unitary gates and projective measurements, both which conserve total $U(1)$ charge thus have symmetry. In addition to measurement-induced entanglement transition between volume-law an area-law entangled phase, we find phase two phases characterized by bipartite fluctuation growing with the subsystem size or staying constan...

We investigate the structure and physical properties of the undoped bilayer silicene through first-principles calculations and find the system is intrinsically metallic with sizable pocket Fermi surfaces. When realistic electron-electron interaction turns on, the system is identified as a chiral d+id' topological superconductor mediated by the strong spin fluctuation on the border of the antife...

A phase transition in an organic charge-transfer complex, which originates from the neutral-ionic valence instability, can be tuned toward zero kelvin with use of external pressure or chemical modification as a control parameter. The phase diagram and observed dielectric behaviors are typical of quantum paraelectricity, yet this zero-kelvin transition point namely, the quantum critical point, a...

We study a microscopic model for a disordered superlattice system, which simulates the effect of intrinsic alloy fluctuation on localization in alloy superlattices. Numerical investigation of scaling behavior of the localization length shows that excitations along and perpendicular to the superlattice axis undergo a localization transition at a nonzero critical disorder. Therefore, we contend t...

A sequence of Galton–Watson branching processes with immigration is investigated, when the offspring mean tends to its critical value one and the offspring variance tends to zero. It is shown that the fluctuation limit is an Ornstein– Uhlenbeck type process. As a consequence, in contrast to the case where the offspring variance tends to a positive limit, the conditional least squares estimator ...