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Quantile regression (QR) is a statistical tool for distribution-free estimation of conditional quantiles of a target variable given explanatory features. QR is limited by the assumption that the target distribution is univariate and defined…

Calculating molecular properties using quantum devices can be done through the quantum linear response (qLR) or, equivalently, the quantum equation of motion (qEOM) formulations. Different parameterizations of qLR and qEOM are available,…

We study the decoherence of a quantum computer in an environment which is inherently correlated in time and space. We first derive the nonunitary time evolution of the computer and environment in the presence of a stabilizer error…

Quantum Physics · Physics 2007-05-23 E. Novais , Harold U. Baranger

The quantum Rabi model (QRM) is a fundamental model for light-matter interactions. A fascinating feature of the QRM is that it manifests a quantum phase transition which is applicable for critical quantum metrology (CQM). Effective…

Quantum Physics · Physics 2024-09-20 Zu-Jian Ying , Wen-Long Wang , Bo-Jian Li

Determination of the quantum nature of correlations between two spatially separated systems plays a crucial role in quantum information science. Of particular interest is the questions of if and how these correlations enable quantum…

Quantum Physics · Physics 2017-09-27 Farid Shahandeh , Austin P. Lund , Timothy C. Ralph

This paper continues on the program of developing a relativistic quantum information theory in terms of unequal-time correlation functions in quantum field theory (QFT)[arXiv:2208.03696]. Here, we focus on the definition of quantum…

Quantum Physics · Physics 2024-11-19 Charis Anastopoulos , Konstantina Savvidou

We present a theory of finite-frequency noise in non-equilibrium conductors. It is shown that Non-Markovian correlations are essential to describe the physics of quantum noise. In particular, we show the importance of a correct treatment of…

Mesoscale and Nanoscale Physics · Physics 2011-04-01 D. Marcos , C. Emary , T. Brandes , R. Aguado

By employing the spin-boson model in a dense limit of environmental modes, quantum entanglement and correlation of sub-Ohmic and Ohmic baths for dissipative quantum phase transitions are numerically investigated based on the variational…

Quantum Physics · Physics 2022-02-08 Xiaohui Qian , Zhe Sun , Nengji Zhou

Quantum periodic cluster methods for strongly correlated electron systems are reformulated and developed. The reformulation and development are based on a canonical transformation which periodizes the fermions in the cluster space. The…

Strongly Correlated Electrons · Physics 2007-05-23 Tran Minh-Tien

The VQE algorithm has turned out to be quite expensive to run given the way we currently access quantum processors (i.e. over the cloud). In order to alleviate this issue, we introduce Quantum Sampling Regression (QSR), an alternative…

Quantum Physics · Physics 2020-12-07 Pedro Rivero , Ian C. Cloët , Zack Sullivan

We consider a finite one-dimensional chain of quantum rotors interacting with a set of thermal baths at different temperatures. When the interaction between the rotors is made chiral, such a system behaves as an autonomous thermal motor,…

Quantum Physics · Physics 2022-11-08 Ricardo Puebla , Alberto Imparato , Alessio Belenchia , Mauro Paternostro

Correlations of fluctuations are the driving forces behind the dynamics and thermodynamics in quantum many-body systems. For qubits embedded in a quantum bath, the correlations in the bath are the key to understanding and combating…

Quantum Physics · Physics 2019-08-07 Ping Wang , Chong Chen , Xinhua Peng , Jorg Wrachtrup , Ren-Bao Liu

We initiate the systematic study of experimental quantum physics from the perspective of computational complexity. To this end, we define the framework of quantum algorithmic measurements (QUALMs), a hybrid of black box quantum algorithms…

Quantum Physics · Physics 2022-03-09 Dorit Aharonov , Jordan Cotler , Xiao-Liang Qi

Semiconductor quantum dots operated dynamically are the basis of many quantum technologies such as quantum sensors and computers. Hence, modelling their electrical properties at microwave frequencies becomes essential to simulate their…

Mesoscale and Nanoscale Physics · Physics 2024-10-24 L. Peri , G. A. Oakes , L. Cochrane , C. J. B. Ford , M. F. Gonzalez-Zalba

Variational methods have proven to be excellent tools to approximate ground states of complex many body Hamiltonians. Generic tools like neural networks are extremely powerful, but their parameters are not necessarily physically motivated.…

Strongly Correlated Electrons · Physics 2022-03-04 Agnes Valenti , Eliska Greplova , Netanel H. Lindner , Sebastian D. Huber

The principle of microscopic reversibility is a fundamental element in the formulation of fluctuation relations and the Onsager reciprocal relations. As such, a clear description of whether and how this principle is adapted to the quantum…

Quantum Physics · Physics 2023-10-25 K. Khan , W. F. Magalhaes , Jailson S. Araujo , B. de Lima Bernardo , Gabriel H. Aguilar

Classical realism demands that system properties exist independently of whether they are measured, while noncontextuality demands that the results of measurements do not depend on what other measurements are performed in conjunction with…

Variational Quantum Circuits are being used as versatile Quantum Machine Learning models. Some empirical results exhibit an advantage in supervised and generative learning tasks. However, when applied to Reinforcement Learning, less is…

Quantum Physics · Physics 2023-01-18 André Sequeira , Luis Paulo Santos , Luís Soares Barbosa

The influence of dissipation on quantum tunneling in the spin-boson model with a sub-Ohmic bath is studied by a variational calculation. By examining the evolution of solutions of the variational equation with the coupling strength near the…

Strongly Correlated Electrons · Physics 2007-05-23 Hang Wong , Zhi-De Chen

We investigate the quantum thermal transistor effect in nonequilibrium three-level systems by applying the polaron transformed Redfield equation combined with full counting statistics. The steady state heat currents are obtained via this…

Quantum Physics · Physics 2020-08-26 Chen Wang , Dazhi Xu