Tootfinder

Natural Excitation Framework for Defining the External Space: Uncontracted and Internally Contracted Multireference Nonorthogonal Wavefunction Theories
Matheus M. F. Moraes, Lee M. Thompson
https://arxiv.org/abs/2509.25436

Natural Excitation Framework for Defining the External Space: Uncontracted and Internally Contracted Multireference Nonorthogonal Wavefunction Theories
In this communication, we examine new formalisms for the construction of the external space when correlating reference wavefunctions built from nonorthogonal determinant expansions. Defining the external space in nonorthogonal approaches is challenging, as every substitution from the reference wavefunction can potentially mix both internal and external configurations. As a result, post-nonorthogonal methods are plagued by internal contamination and linear dependencies in the external space, whi…

Spin-basis wavefunctions for the one-dimensional Kitaev model
Alwyn Jose Raja, Rajesh Narayanan, R. Ganesh
https://arxiv.org/abs/2509.21771 https://arxiv.o…

Spin-basis wavefunctions for the one-dimensional Kitaev model
Magnetic phases with quantum entanglement are often expressed in terms of parton wavefunctions. Relatively few examples are known where wavefunctions can be directly written down in the spin basis. In this article, we consider the spin-$S$ Kitaev model in one dimension. For $S=1/2$, its eigenstates can be written using a Jordan-Wigner fermionic representation. Here, we present ground state wavefunctions for any $S$ directly in the spin basis. The states we propose are valence bond arrangements,…

Enabling full localization of qubits and gates with a multi-mode coupler
Zhongyi Jiang, Simon Geisert, S\"oren Ihssen, Ioan M. Pop, Mohammad H. Ansari
https://arxiv.org/abs/2509.26211

Enabling full localization of qubits and gates with a multi-mode coupler
Tunable couplers are a key building block of superconducting quantum processors, enabling high on-off ratios for two-qubit entangling interactions. While crosstalk can be mitigated in idle mode, conventional single-mode couplers lack independent control over interactions in the one- and two-excitation manifolds, leading to unitary errors such as leakage during gate operations. Moreover, even at the nominal decoupled point, residual wavefunction delocalization persists, causing unintended qubit-…

Scattering of Quantum Particles in Global de Sitter Spacetime II: Scalars in Deep Infrared
Tomasz R. Taylor, Bin Zhu
https://arxiv.org/abs/2509.25407 https://

Scattering of Quantum Particles in Global de Sitter Spacetime II: Scalars in Deep Infrared
We apply the S-matrix formalism developed in Part I to the interacting scalar theory in four-dimensional de Sitter spacetime. The amplitudes are computed in the angular momentum basis, appropriate to the representations of $SO(1,4)$ de Sitter symmetry group. We discuss the properties of wavefunctions in Bunch-Davies vacuum and derive a new integral representation for the Feynman propagator. We focus on deep infrared processes probing the large scale structure of spacetime, in particular on the …

Monte Carlo quantum cosmology with a modified Euclidean action
Malaik Kabir, Syed Moeez Hassan
https://arxiv.org/abs/2509.25125 https://arxiv.org/pdf/2509.…

Monte Carlo quantum cosmology with a modified Euclidean action
We numerically study the Euclidean quantum cosmology of a closed, homogeneous and isotropic universe with a cosmological constant. A dust field acts as a clock, and we compute the ground state wavefunction, correlation function, and mean volume of the universe by performing path integral Monte Carlo simulations. To make the path integral convergent, the argument of the exponent in the weight of the path integral is chosen to be either the absolute value of the Euclidean action, or its square. W…

Dynamical gluon effects in the three-dimensional structure of pion
Jiangshan Lan, Kaiyu Fu, Satvir Kaur, Zhimin Zhu, Chandan Mondal, Xingbo Zhao, James P. Vary
https://arxiv.org/abs/2509.22016

Dynamical gluon effects in the three-dimensional structure of pion
We investigate the internal structure of the pion, including the contributions from one dynamical gluon, using the basis light-front quantization (BLFQ) approach. By solving a light-front QCD Hamiltonian with a three-dimensional confining potential, we obtain the light-front wavefunctions (LFWFs) for both the quark-antiquark and quark-antiquark-gluon Fock sectors. These wavefunctions are then employed to compute the unpolarized generalized parton distributions (GPDs) and the transverse-momentum…

Anderson localization: a density matrix approach
Ziyue Qi, Yi Zhang, Mingpu Qin, Hongming Weng, Kun Jiang
https://arxiv.org/abs/2509.26206 https://arxiv.or…

Anderson localization: a density matrix approach
Anderson localization is a quantum phenomenon in which disorder localizes electronic wavefunctions. In this work, we propose a new approach to study Anderson localization based on the density matrix formalism. Drawing an analogy to the standard transfer matrix method, we extract the localization length from the modular density matrix in quasi-one-dimensional systems. This approach successfully captures the metal-insulator transition in the three-dimensional Anderson model and in the two-dimensi…

Gauging the Standard Model 1-form symmetry via gravitational instantons
Mohamed M. Anber
https://arxiv.org/abs/2509.22788 https://arxiv.org/pdf/2509.22788

Gauging the Standard Model 1-form symmetry via gravitational instantons
We investigate the fate of the Standard Model (SM) $\mathbb Z_6^{(1)}$ electric $1$-form global symmetry in the background of gravitational instantons, focusing on Eguchi-Hanson (EH) geometries. We show that EH instantons support quantized $\mathbb Z_6^{(1)}$ fluxes localized on their $S^2$ bolt, inducing fractional topological charge without backreacting on the geometry. The requirement that quark and lepton wavefunctions be globally well-defined under parallel transport imposes boundary condi…

Relativistic Quantum Simulation under Periodic and Dirichlet Boundary Conditions: A First-Quantised Framework for Near-Term Devices
Jaewoo Joo, Timothy P. Spiller, Kyunghyun Baek, Jeongho Bang
https://arxiv.org/abs/2509.22579

Relativistic Quantum Simulation under Periodic and Dirichlet Boundary Conditions: A First-Quantised Framework for Near-Term Devices
We present a new recipe for relativistic quantum simulation using the first quantisation approach, under periodic (PBC) and Dirichlet (DBC) boundary conditions. The wavefunction is discretised across a finite grid represented by system qubits, and the squared momentum operator is expressed using the finite-difference method based on quantum translation operations. The relativistic kinetic energy is approximated through a perturbative expansion of the total kinetic Hamiltonian, incorporating hig…

A Markovian Framing of WaveFunctionCollapse for Procedurally Generating Aesthetically Complex Environments
Franklin Yiu, Mohan Lu, Nina Li, Kevin Joseph, Tianxu Zhang, Julian Togelius, Timothy Merino, Sam Earle
https://arxiv.org/abs/2509.09919

A Markovian Framing of WaveFunctionCollapse for Procedurally Generating Aesthetically Complex Environments
Procedural content generation often requires satisfying both designer-specified objectives and adjacency constraints implicitly imposed by the underlying tile set. To address the challenges of jointly optimizing both constraints and objectives, we reformulate WaveFunctionCollapse (WFC) as a Markov Decision Process (MDP), enabling external optimization algorithms to focus exclusively on objective maximization while leveraging WFC's propagation mechanism to enforce constraint satisfaction. We emp…