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In this work we develop an alternative approach for solution of Quantum Trajectories using the Path Integral method. The state-of-the-art technique in the field is to solve a set of non-linear, coupled partial differential equations (PDEs)…

Quantum Physics · Physics 2021-02-16 Sagnik Ghosh , Swapan K. Ghosh

We propose path integral description for quantum mechanical systems on compact graphs consisting of N segments of the same length. Provided the bulk Hamiltonian is segment-independent, scale-invariant boundary conditions given by…

High Energy Physics - Theory · Physics 2012-06-06 Satoshi Ohya

In the context of two illustrative examples from supersymmetric quantum mechanics we show that the semi-classical analysis of the path integral requires complexification of the configuration space and action, and the inclusion of complex…

High Energy Physics - Theory · Physics 2016-01-13 Alireza Behtash , Gerald V. Dunne , Thomas Schaefer , Tin Sulejmanpasic , Mithat Unsal

Quantum coherence is an exquisitely quantum phenomenon that depends on both probability amplitudes and relative phases. Standard coherence measures quantify superposition within density matrices but cannot distinguish ensembles that produce…

Quantum Physics · Physics 2026-05-29 Cameron Hahn , Nishan Ranabhat , Fabio Anza

Born in the intersection between quantum mechanics and general relativity, indefinite causal structure is the idea that in the continuum of time, some sets of events do not have an inherent causal order between them. Process matrices,…

Quantum Physics · Physics 2024-10-08 Omri Shmueli

In this paper we construct a path integral formulation of quantum mechanics on noncommutative phase-space. We first map the system to an equivalent system on the noncommutative plane. Then by applying the formalism of representing a quantum…

High Energy Physics - Theory · Physics 2017-03-02 Sunandan Gangopadhyay , Aslam Halder

Quantum dissipation in thermal environment is investigated, using the path integral approach. The reduced density matrix of the harmonic oscillator system coupled to thermal bath of oscillators is derived for arbitrary spectrum of bath…

High Energy Physics - Theory · Physics 2009-10-30 I. Joichi , Sh. Matsumoto , M. Yoshimura

We consider causality respecting (CR) quantum systems interacting with closed timelike curves (CTCs), within the Deutsch model. We introduce the concepts of popping up and elimination of quantum information and use them to show that…

Quantum Physics · Physics 2018-07-17 Asutosh Kumar , Indranil Chakrabarty , Arun Kumar Pati , Aditi Sen De , Ujjwal Sen

A discrete formulation of the real-time path integral as the expectation value of a functional of paths with respect to a complex probability on a sample space of discrete valued paths is explored. The formulation in terms of complex…

Quantum Physics · Physics 2024-06-06 Wayne Polyzou

We pursue the view that quantum theory may be an emergent structure related to large space-time scales. In particular, we consider classical Hamiltonian systems in which the intrinsic proper time evolution parameter is related through a…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Hans-Thomas Elze

We present a new formulation for the emergence of classical dynamics in a quantum world by considering a path integral approach that also incorporates continuous measurements. Our program is conceptually different from the decoherence…

Quantum Physics · Physics 2025-05-23 Harsh Arora , Bishal Kumar Das , Baladitya Suri , Vaibhav Madhok

Assuming the validity of random matrices for describing the statistics of a closed chaotic quantum system, we study analytically some statistical properties of the S-matrix characterizing scattering in its open counterpart. In the first…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 Yan. V. Fyodorov , H. -J. Sommers

Dirac particle dynamics is encoded as a unitary path summation rule and implemented on a qubit array, where the qubit array represents both spacetime and the fermions contained therein. The unitary path summation rule gives a quantum…

Quantum Physics · Physics 2017-08-15 Jeffrey Yepez

Quantum computing is finding promising applications in optimization, machine learning and physics, leading to the development of various models for representing quantum information. Because these representations are often studied in…

Quantum Physics · Physics 2024-01-03 Lieuwe Vinkhuijzen , Tim Coopmans , Alfons Laarman

With a choice of boundary conditions for solutions of the Schr\"odinger equation, state vectors and density operators even for closed systems evolve asymmetrically in time. For open systems, standard quantum mechanics consequently predicts…

Quantum Physics · Physics 2010-05-25 P. W. Bryant

Quantum walks constitute important tools in different applications, especially in quantum algorithms. To a great extent their usefulness is due to unusual diffusive features, allowing much faster spreading than their classical counterparts.…

Quantum Physics · Physics 2012-10-09 F. M. Andrade , M. G. E. da Luz

In recent years dual-unitary circuits and their multi-unitary generalizations have emerged as exactly solvable yet chaotic models of quantum many-body dynamics. However, a systematic picture for the solvability of multi-unitary dynamics…

Quantum Physics · Physics 2025-12-19 Michael A. Rampp , Suhail A. Rather , Pieter W. Claeys

The quantum density matrix generalises the classical concept of probability distribution to quantum theory. It gives the complete description of a quantum state as well as the observable quantities that can be extracted from it. Its…

Quantum Physics · Physics 2023-08-31 Apoorva D. Patel

The path integral approach offers not only an exact expression for the non- equilibrium dynamics of dissipative quantum systems, but is also a convenient starting point for perturbative treatments. An alternative way to explore the…

Statistical Mechanics · Physics 2022-09-21 Joachim Ankerhold

Many results have been recently obtained regarding the power of hypothetical closed time-like curves (CTCs) in quantum computation. Here we show that the one-way model of measurement-based quantum computation encompasses in a natural way…

Quantum Physics · Physics 2011-01-27 Raphael Dias da Silva , Ernesto F. Galvao , Elham Kashefi