arXiv subjects

Noah Hassan

Publications and source records attributed to Noah Hassan.

3 recordsLinked to original sources

arXiv2026

Thermodynamics of the Heisenberg antiferromagnet on the maple-leaf lattice

We study the Heisenberg antiferromagnet on the maple-leaf lattice using several numerical approaches, focusing on the numerical linked-cluster expansion (NLCE), which exhibits an unconventional convergence extending to low and even zero temperatures. We evaluate thermodynamic properties as well as spin-spin correlations through the equal-time structure factor. Within NLCE the specific heat capacity reveals a two-peak structure at $T_1 \approx 0.479\,J$ and $T_2 \approx 0.131\,J$, reminiscent of the corresponding result for the triangular lattice. At intermediate temperatures, the spin-spin structure factor develops features that reflect the absence of reflection symmetry in the lattice. The zero-temperature convergence of NLCE enables reliable estimates of the ground-state energy and points to a short-range correlated paramagnetic ground state composed of resonating hexagonal motifs. The NLCE results are benchmarked against Pseudo-Majorana Functional Renormalization Group, finite-temperature Lanczos, and classical Monte Carlo simulations.

cond-mat.str-el↗

arXiv2024

Off-Shell Quantum Mechanics as Factorization Algebras on Intervals

We present, for the harmonic oscillator and the spin-$\frac{1}{2}$ system, an alternative formulation of quantum mechanics that is `off-shell': it is based on classical off-shell configurations and thus similar to the path integral. The core elements are Batalin-Vilkovisky (BV) algebras and factorization algebras, following a program by Costello and Gwilliam. The BV algebras are the spaces of quantum observables ${\rm Obs}^q(I)$ given by the symmetric algebra of polynomials in compactly supported functions on some interval $I\subset\mathbb{R}$, which can be viewed as functionals on the dynamical variables. Generalizing associative algebras, factorization algebras include in their data a topological space, which here is $\mathbb{R}$, and an assignment of a vector space to each open set, which here is the assignment of ${\rm Obs}^q(I)$ to each open interval $I$. The central structure maps are bilinear ${\rm Obs}^q(I_1)\otimes {\rm Obs}^q(I_2)\rightarrow {\rm Obs}^q(J)$ for disjoint intervals $I_1$ and $I_2$ contained in an interval $J$, which here is the wedge product of the symmetric algebra. We prove, as the central result of this paper, that this factorization algebra is quasi-isomorphic to the factorization algebra of `on-shell' quantum mechanics. In this we extend previous work by including half-open and closed intervals, and by generalizing to the spin-$\frac{1}{2}$ system.

hep-th↗

arXiv2022

A Search for Low-mass Dark Matter via Bremsstrahlung Radiation and the Migdal Effect in SuperCDMS

In this paper, we present a re-analysis of SuperCDMS data using a profile likelihood approach to search for sub-GeV dark matter particles (DM) through two inelastic scattering channels: bremsstrahlung radiation and the Migdal effect. By considering possible inelastic scattering channels, experimental sensitivity can be extended to DM masses that would otherwise be undetectable through the DM-nucleon elastic scattering channel, given the energy threshold of current experiments. We exclude DM masses down to $220~\textrm{MeV}/c^2$ at $2.7 \times 10^{-30}~\textrm{cm}^2$ via the bremsstrahlung channel. The Migdal channel search excludes DM masses down to $30~\textrm{MeV}/c^2$ at $5.0 \times 10^{-30}~\textrm{cm}^2$.

hep-ex↗