Rare 3p decay events from excited ^13N^ states are a sensitive tool for exploring cluster configurations in the ^13N^ nucleus. The low-energy products consequent to -delayed 3p decay were measured with the Texas Active Target (TexAT) time projection chamber, a tool that utilized the one-at-a-time delayed charged-particle spectroscopy approach at the Cyclotron Institute, Texas A&M University. Implantation procedures, totaling 1910^5 ^13O, were carried out inside the TexAT time projection chamber. The tally of three-prime events reached 149, determining a -delayed three-prime branching ratio of 0.0078(6) percent. The 3+p decay channel was responsible for the disintegration of four novel -decaying excited states of ^13N, situated at excitation energies of 113, 124, 131, and 137 MeV.
Employing contact topology, we present a complete topological classification of defect lines within cholesteric liquid crystals. Our study, rooted in the material's chirality, demonstrates a fundamental divergence between tight and severely twisted disclination lines, a divergence not uncovered by typical homotopy theory. The classification of overtwisted lines parallels that of nematics; nevertheless, we show that a consistent topological layer number is characteristic of tight disclinations, provided the twist does not vanish. Ultimately, we demonstrate that chirality impedes the release of removable defect lines, and explain how this impediment drives the development of diverse structures in experimental observations.
In the presence of a background gauge field coupling, topological zero modes often manifest as an anomalous current at the interface, resulting in the zero-mode anomaly inflow, which is ultimately balanced by contributions from the topological bulk. However, the mechanism for guiding Floquet steady states through anomaly inflow in periodically driven systems remains underexplored. This driven topological-normal insulator heterostructure is synthesized, and we propose a Floquet gauge anomaly inflow that is associated with the manifestation of arbitrary fractional charge. A Floquet gauge anomaly, as observed experimentally via our photonic modeling, manifested itself as the system transitioned into anomalous topological phases. Our observations suggest a promising new direction for examining Floquet gauge anomalies within driven systems of condensed matter, photonics, and ultracold atoms.
The complexities of the two-dimensional (2D) Hubbard model pose one of the most demanding challenges for accurate simulation in condensed matter and quantum physics. Calculations of the 2D Hubbard model at finite temperature are undertaken using a tangent space tensor renormalization group (tanTRG) technique. The density operator evolves optimally in tanTRG with a computational burden of O(D^3), with the accuracy of the result being dictated by the bond dimension D. The tanTRG technique allows for improved calculations of low-temperature properties in extensive 2D Hubbard models, reaching up to 8-wide cylinders and 10^10-square lattices. The results obtained for the half-filled Hubbard model demonstrate remarkable consistency with those produced by determinant quantum Monte Carlo (DQMC). Moreover, tanTRG enables the investigation of the low-temperature, limited-doping region, which is not accessible using DQMC. Analysis reveals that the calculated charge compressibility and Matsubara Green's function mirror the strange metal and pseudogap behaviors, respectively. The computational analysis of superconductive pairing susceptibility is carried out down to a low temperature, roughly one-twenty-fourth of the hopping energy, where the d-wave pairing response is most pronounced near optimal doping. The tangent-space technique is fundamental to tanTRG's status as a highly accurate and efficient tensor network method for analyzing 2D lattice models with strong correlations at finite temperatures.
Fascinating nonequilibrium heating is observed in quantum spin liquids subjected to a periodic drive, originating from their emergent fractionalized quasiparticles. The dynamics of Majorana matter and Z2 flux excitations within a driven Kitaev honeycomb model are scrutinized in this investigation. A distinctive two-phase heating profile, termed fractionalized prethermalization, and a quasi-stationary state show a dramatic difference in temperatures between the matter and flux sectors. We posit that the observed prethermalization behavior is a result of fractionalization. Furthermore, a demonstrably feasible protocol for constructing a zero-flux initial state within the Kiteav honeycomb model, with a low energy density, is presented, enabling observation of fractionalized prethermalization in quantum information processing systems.
Density-functional theory allows for the prediction of both the frequency and dipole moment of molecular crystal's fundamental oscillations. Such oscillations are brought about by suitably polarized photons at those specific frequencies. Hence, the application of terahertz spectroscopy can serve to substantiate the calculated fundamental vibrational modes of amino acids. US guided biopsy Present reports, however, suffer from critical weaknesses: (a) the material, with uncertain purity and structure, is diluted within a binder; (b) this results in simultaneous vibration excitation along all crystal axes; (c) data are limited to room temperature where resonances are wide and background noise is prominent; and (d) comparison with theory is unsatisfactory (due to the theory's zero-temperature assumption). Mobile genetic element Detailed low-temperature polarized THz spectra of single-crystal l-alanine, overcoming all four obstacles, are presented by assigning vibrational modes with density-functional theory and comparing the calculated dipole moment vector direction to the electric field polarization in the measured spectra. Our direct and detailed experimental validation of theoretical models for l-alanine corrected previous mode assignments, exposing hidden modes previously masked by closely spaced spectral absorptions. Accordingly, the fundamental modes are determined.
Using the saddle point approximation to leading order, we evaluate the quantum gravity partition function, which computes the dimension of the Hilbert space in a spatial region having a ball topology, subject to a fixed proper volume. The result, the exponential of the Bekenstein-Hawking entropy based on the area of the saddle ball boundary, is validated within effective field theory if the mild curvature singularity at the ball boundary is managed by terms incorporating higher curvature. The de Sitter entropy calculation of Gibbons and Hawking is generalized for positive cosmological constants and unconstrained volumes, revealing the holographic underpinnings of nonperturbative quantum gravity in finite spatial geometries.
Prognosticating the eventual outcome for a system with interacting components, when electronic bandwidth is diminished, often presents a significant complexity. Competition amongst ground states, including charge density wave order and superconductivity, can arise from the complex relationship between band geometry, quantum fluctuations, and interactions. Employing numerically exact quantum Monte Carlo simulations, we examine an electronically modeled system of topologically trivial flat bands. This system features a continuously adjustable Fubini-Study metric, along with on-site attraction and nearest-neighbor repulsion. Through variations in electron filling and the smallest possible spatial extent of the localized flat-band Wannier wave functions, we produce numerous intertwined orders. A phase possessing both charge density wave order and superconductivity demonstrates the characteristic behavior of a supersolid. Notwithstanding the non-perturbative nature of the problem, we recognize an analytically manageable limit due to the small spatial scope of the Wannier functions, and derive a low-energy effective Hamiltonian that mirrors our numerical findings. We provide compelling evidence for the violation of any proposed lower limit on the zero-temperature superfluid rigidity in geometrically complex flat bands.
The degrees of freedom stemming from relative density fluctuations in a two-component Bose-Einstein condensate are described by a nondissipative Landau-Lifshitz equation near the demixing transition. This mapping, surprisingly, predicts that, in the quasi-one-dimensional case of weakly immiscible components, a dark-bright soliton will oscillate when a constant force favors the separation of the two. This phenomenon, which we interpret as a spin-Josephson effect, is realized experimentally with a movable barrier, presented as a realistic implementation.
We introduce random walks that exhibit range control, where the hopping rates depend on N, the total number of distinct previously visited locations. We examine a family of models parameterized by a single variable, featuring a hopping rate proportional to N raised to the power of a, and investigate the long-term behavior of the mean range, encompassing its complete distribution across two distinct limiting scenarios. The behavior is fundamentally altered depending on the relative size of exponent 'a' to the critical value 'a_d', which in turn depends only on the spatial dimension 'd'. A value of a exceeding a d results in the forager covering the infinite lattice in a finite time. With d squared as a condition, the critical exponent is 1/2, while d equals 1. In addition, we explore the case of two foragers competing for food, their hopping rates varying according to the respective counts of locations each has surveyed prior to the other. Docetaxel When 'a' is greater than one, a single walker prominently occupies the majority of sites within a one-dimensional framework; conversely, when 'a' is less than one, the walkers distribute themselves evenly along the line. We quantify the efficiency gain in site visits by including an additional walker.