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1. Autocorrelation properties of temporal networks governed by dynamic node variables

   https://doi.org/10.1103/PhysRevResearch.7.013083  

   Hartle, Harrison; Masuda, Naoki (January 2025, Physical Review Research)

   We study synthetic temporal networks whose evolution is determined by stochastically evolving node variables—synthetic analogues of, e.g., temporal proximity networks of mobile agents. We quantify the long-timescale correlations of these evolving networks by an autocorrelative measure of network-structural memory. Several distinct patterns of autocorrelation arise, including power-law decay and exponential decay, depending on the choice of node-variable dynamics and connection probability function. Our methods are also applicable in wider contexts; our temporal network models are tractable mathematically and in simulation, and our long-term memory quantification is analytically tractable and straightforwardly computable from temporal network data. Published by the American Physical Society2025 

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2. Entanglement and interface conditions on fields

   https://doi.org/10.1103/PhysRevD.111.105027  

   Maj, Antonina; Nair, V P (May 2025, Physical Review D)

   We consider the vacuum wave function of a free scalar field theory in space partitioned into two regions, with the field obeying Robin conditions (of parameter $\kappa$) on the interface. A direct integration over fields in a subregion is carried out to obtain the reduced density matrix. This leads to a constructive proof of the Reeh-Schlieder theorem. We analyze the entanglement entropy as a function of the Robin parameter $\kappa$. We also consider a specific conditional probability as another measure of entanglement which is more amenable to analysis of the dependence on interface conditions. Finally, we discuss a direct calculation of correlation functions and how it gives an alternate route to the reduced density matrix. Published by the American Physical Society2025 

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3. Toward extracting the scattering phase shift from integrated correlation functions. II. A relativistic lattice field theory model

   https://doi.org/10.1103/PhysRevD.110.014504  

   Guo, Peng (July 2024, Physical Review D)

   In the present work, a relativistic relation that connects the difference of interacting and noninteracting integrated two-particle correlation functions in finite volume to infinite volume scattering phase shift through an integral is derived. We show that the difference of integrated finite volume correlation functions converges rapidly to its infinite volume limit as the size of the periodic box is increased. The fast convergence of our proposed formalism is illustrated by analytic solutions of a contact interaction model, the perturbation theory calculation, and also the Monte Carlo simulation of a complex ${\varphi }^4$lattice field theory model. Published by the American Physical Society2024 

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4. Evidence for nonzero electron velocity at the tunnel exit in strong-field atomic ionization

   https://doi.org/10.1103/PhysRevResearch.6.023049  

   Ivanov, I A; Kheifets, A S; Schimmoller, A; Landsman, A S; Kim, Kyung Taec (April 2024, Physical Review Research)

   We provide some evidence for nonzero electron velocity at the tunnel exit in strong-field atomic ionization. Our investigation is based on the analysis of a suitably chosen correlation function which describes correlations between the two observables: the longitudinal electron velocity and the appearance of the photoelectron in the continuum at the end of the laser pulse. The results of the correlation function analysis that we perform are confirmed by the calculations using the quantum orbits method. Published by the American Physical Society2024 

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5. Simulating Open Quantum Systems Using Hamiltonian Simulations

   https://doi.org/10.1103/PRXQuantum.5.020332  

   Ding, Zhiyan; Li, Xiantao; Lin, Lin (May 2024, PRX Quantum)

   We present a novel method to simulate the Lindblad equation, drawing on the relationship between Lindblad dynamics, stochastic differential equations, and Hamiltonian simulations. We derive a sequence of unitary dynamics in an enlarged Hilbert space that can approximate the Lindblad dynamics up to an arbitrarily high order. This unitary representation can then be simulated using a quantum circuit that involves only Hamiltonian simulation and tracing out the ancilla qubits. There is no need for additional postselection in measurement outcomes, ensuring a success probability of one at each stage. Our method can be directly generalized to the time-dependent setting. We provide numerical examples that simulate both time-independent and time-dependent Lindbladian dynamics with accuracy up to the third order. Published by the American Physical Society2024 

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