English
Related papers

Related papers: Few-photon scattering and emission from open quant…

200 papers

Due to random dopant fluctuations, the device-to-device variability is a serious challenge to emerging nanoelectronics. In this work we present theoretical formalisms and numerical simulations of quantum transport variability, based on the…

Mesoscale and Nanoscale Physics · Physics 2013-11-14 Yu Zhu , Lei Liu , Hong Guo

We use the free evolution propagator to determine the quantum probability representation (i.e., the general expression of the tomogram) of any one-dimensional system described by a density state. The evolution operator for the considered…

We present a time-linear scaling method to simulate open and correlated quantum systems out of equilibrium. The method inherits from many-body perturbation theory the possibility to choose selectively the most relevant scattering processes…

Mesoscale and Nanoscale Physics · Physics 2025-06-10 R. Tuovinen , Y. Pavlyukh , E. Perfetto , G. Stefanucci

We apply our recently developed theory of frequency-filtered and time-resolved N-photon correlations to study the two-photon spectra of a variety of systems of increasing complexity: single mode emitters with two limiting statistics (one…

Quantum Physics · Physics 2014-03-06 A. Gonzalez-Tudela , F. P. Laussy , C. Tejedor , M. J. Hartmann , E. del Valle

This paper derives master equations for an atomic two-level system for a large set of unitarily equivalent Hamiltonians without employing the rotating wave and certain Markovian approximations. Each Hamiltonian refers to physically…

Quantum Physics · Physics 2015-06-03 Adam Stokes , Andreas Kurcz , Tim P. Spiller , Almut Beige

In this work we intend to study a class of time-dependent quantum systems with non-Hermitian Hamiltonians, particularly those whose Hermitian counterpart are important for the comprehension of posed problems in quantum optics and quantum…

Quantum Physics · Physics 2007-05-23 A. de Souza Dutra , M. B. Hott , V. G. C. S dos Santos

In this work we solve exactly a class of three-body propagators for the most general quadratic interactions in the coordinates, for arbitrary masses and couplings. This is done both for the constant as the time-dependent couplings and…

Quantum Physics · Physics 2009-11-13 A. de Souza Dutra

The multiple-quantum operator algebra formalism has been exploited to construct generally an unsorted quantum search algorithm. The exponential propagator and its corresponding effective Hamiltonian are constructed explicitly that describe…

Quantum Physics · Physics 2007-05-23 Xijia Miao

We present an exact closed-form expression for the propagator of the Calogero model, i.e., for the integral kernel of the time evolution operator of the quantum many-body system on the real line with an external harmonic potential and…

Quantum Physics · Physics 2025-01-30 Valdemar Melin , Edwin Langmann

We develop an approach to calculate the admittance of effectively one-dimensional open quantum systems in random phase approximation. The stationary, unperturbed system is described within the Landauer-B\"uttiker formalism taking into…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 U. Wulf , P. N. Racec , E. R. Racec

We develop a new computational tool and framework for characterizing the scattering of photons by energy-nonconserving Hamiltonians into unidirectional (chiral) waveguides, for example, with coherent pulsed excitation. The temporal…

Quantum Physics · Physics 2018-05-30 Kevin A. Fischer , Rahul Trivedi , Vinay Ramasesh , Irfan Siddiqi , Jelena Vučković

We study certain aspects of the effective, occasionally called collective, description of complex quantum systems within the framework of the path integral formalism, in which the environment is integrated out. Generalising the standard…

Statistical Mechanics · Physics 2007-05-23 U. Eckern , M. J. Gruber , P. Schwab

The Feynman propagator used in the conventional in-out formalism in quantum field theory is not a causal propagator as wave packets are propagated virtually instantaneously outside the causal region of the initial state. We formulate a…

High Energy Physics - Theory · Physics 2010-12-17 Jurjen F. Koksma , W. Westra

Accurate computation of the Green's function is crucial for connecting experimental observations to the underlying quantum states. A major challenge in evaluating the Green's function in the time domain lies in the efficient simulation of…

Quantum Physics · Physics 2025-09-12 Lingyun Wan , Jie Liu , Jinlong Yang

We provide an analytic propagator for non-Hermitian dimers showing linear gain or losses in the quantum regime. In particular, we focus on experimentally feasible realizations of the $\mathcal{PT}$-symmetric dimer and provide their mean…

Quantum Physics · Physics 2017-08-09 José Delfino Huerta Morales , B. M. Rodríguez-Lara

We study spectral properties of a non-Hermitian Hamiltonian describing a quantum particle propagating in a random imaginary scalar potential. Cast in the form of an effective field theory, we obtain an analytical expression for the ensemble…

Disordered Systems and Neural Networks · Physics 2009-10-31 A. V. Izyumov , B. D. Simons

Linear optical networks are devices that turn classical incident modes by a linear transformation into outgoing ones. In general, the quantum version of such transformations may mix annihilation and creation operators. We derive a simple…

Quantum Physics · Physics 2009-11-10 U. Leonhardt , A. Neumaier

Computation of the Green's function is crucial to study the properties of quantum many-body systems such as strongly correlated systems. Although the high-precision calculation of the Green's function is a notoriously challenging task on…

The $2 \times 2$-matrix structure of Green's functions is a common feature for the real-time formalisms of quantum field theory under thermal situations, such as the closed time path formalism and Thermo Field Dynamics (TFD). It has been…

Quantum Physics · Physics 2015-06-16 Y. Kuwahara , Y. Nakamura , Y. Yamanaka

We propose an improved quantum algorithm to calculate the Green's function through real-time propagation, and use it to compute the retarded Green's function for the 2-, 3- and 4-site Hubbard models. This novel protocol significantly…

Quantum Physics · Physics 2022-10-21 Francesco Libbi , Jacopo Rizzo , Francesco Tacchino , Nicola Marzari , Ivano Tavernelli