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Noise and errors are unavoidable in any realistic quantum process, including processes designed to reduce noise and errors in the first place. In particular, quantum thermodynamical protocols for cooling can be significantly affected,…

Quantum Physics · Physics 2026-01-26 Jian Li , Xiaoyang Wang , Marcus Huber , Nicolai Friis , Pharnam Bakhshinezhad

We study mesoscopic resonant tunneling as well as multichannel Kondo problems by mapping them to a first-quantized quantum mechanical model of a particle moving in a multi-dimensional periodic potential with Ohmic dissipation. From a…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Hangmo Yi

The eigenstates of an isolated nanostructure may get mixed by the coupling to external leads. This effect is the stronger, the smaller the level splitting on the dot and the larger the broadening induced by the coupling to the leads. We…

Strongly Correlated Electrons · Physics 2008-04-22 V. Koerting , J. Paaske , P. Wölfle

We consider the out-of-equilibrium behavior of a general class of mesoscopic devices composed of several superconducting or/and normal metal leads separated by quantum dots. Starting from a microscopic Hamiltonian description, we provide a…

Superconductivity · Physics 2020-09-02 R. Jacquet , A. Popoff , K. -I. Imura , J. Rech , T. Jonckheere , L. Raymond , A. Zazunov , T. Martin

Learned denoisers play a fundamental role in various signal generation (e.g., diffusion models) and reconstruction (e.g., compressed sensing) architectures, whose success derives from their ability to leverage low-dimensional structure in…

Machine Learning · Computer Science 2025-08-14 Shiyu Wang , Mariam Avagyan , Yihan Shen , Arnaud Lamy , Tingran Wang , Szabolcs Márka , Zsuzsa Márka , John Wright

Understanding how noise degrades entanglement is crucial for the development of reliable quantum technologies. While the Markovian approximation simplifies the analysis of noise, it remains computationally demanding, particularly for…

Quantum Physics · Physics 2026-01-27 Nunzia Cerrato , Sauro Succi , Giacomo De Palma , Vittorio Giovannetti

We apply a dynamical systems approach to concatenation of quantum error correcting codes, extending and generalizing the results of Rahn et al. [1] to both diagonal and nondiagonal channels. Our point of view is global: instead of focusing…

Quantum Physics · Physics 2007-05-23 Jesse Fern , Julia Kempe , Slobodan Simic , Shankar Sastry

Do stochastic Schr\"odinger equations, also known as unravelings, have a physical interpretation? In the Markovian limit, where the system {\em on average} obeys a master equation, the answer is yes. Markovian stochastic Schr\"odinger…

Quantum Physics · Physics 2009-11-07 Jay Gambetta , H. M. Wiseman

We investigate the transport through a few-level quantum system described by a Markovian master equation with temperature- and particle-density dependent chemical potentials. From the corresponding Onsager relations we extract linear…

Quantum Gases · Physics 2014-02-03 Christian Nietner , Gernot Schaller , Tobias Brandes

Atomic scale qubits, as may be realized in nitrogen vacancy (NV) centers in diamond, offer the opportunity to study magnetic field noise with nanometer scale spatial resolution. Using these spin qubits, one can learn a great deal about the…

Quantum Physics · Physics 2025-06-24 Jonathan B. Curtis , Amir Yacoby , Eugene Demler

We investigate sequential tunneling through a multilevel quantum dot confining multiple electrons, in the regime where several channels are available for transport within the bias window. By analyzing solutions to the master equations of…

Mesoscale and Nanoscale Physics · Physics 2009-02-23 Eduardo Vaz , Jordan Kyriakidis

Recent work has revealed a general procedure for incorporating disorder into the semiclassical model of carrier transport, whereby the predictions of quantum linear response theory can be recovered within a quantum kinetic approach based on…

Mesoscale and Nanoscale Physics · Physics 2025-03-10 M. Mehraeen

We demonstrate that with a stepwise introduction of complexity to a model of an electron system embedded in a photonic cavity and a carefully controlled stepwise truncation of the ensuing many-body space it is possible to describe the…

Mesoscale and Nanoscale Physics · Physics 2013-07-01 Vidar Gudmundsson , Olafur Jonasson , Thorsten Arnold , Chi-Shung Tang , Hsi-Sheng Goan , Andrei Manolescu

We investigate the non-Markovian characteristics in continuous measurement of a charge qubit by a quantum point contact. The backflow of information from the reservoir to the system in the non-Markovian domain gives rise to strikingly…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 JunYan Luo , HuJun Jiao , Xiao-Li Lang , BiTao Xiong , Xiao-Ling He

We derive simple expressions that relate the noise and correlation properties of a general time-dependent quantum conductor to the wave functions of the system. The formalism provides a practical route for numerical calculations of quantum…

Mesoscale and Nanoscale Physics · Physics 2015-10-22 Benoit Gaury , Xavier Waintal

We investigate sequential tunneling transport through a semiconductor double quantum dot structure by combining a simple microscopic quantum confinement model with a Mott-Hubbard type correlation model. We calculate nonperturbatively the…

Mesoscale and Nanoscale Physics · Physics 2009-10-28 R. Kotlyar , S. Das Sarma

We study the dynamics of quantum systems under classical and quantum noise, focusing on decoherence in qubit systems. Classical noise is described by a random process leading to a stochastic temporal evolution of a closed quantum system,…

Quantum Physics · Physics 2010-10-25 Olli-Pentti Saira , Ville Bergholm , Teemu Ojanen , Mikko Mottonen

In former work, quantum computation has been shown to be a problem solving process essentially affected by both the reversible dynamics leading to the state before measurement, and the logical-mathematical constraints introduced by quantum…

Quantum Physics · Physics 2007-05-23 Giuseppe Castagnoli

Variational quantum algorithms rely on the optimization of parameterized quantum circuits in noisy settings. The commonly used back-propagation procedure in classical machine learning is not directly applicable in this setting due to the…

Quantum Physics · Physics 2024-08-27 Zhiyan Ding , Taehee Ko , Jiahao Yao , Lin Lin , Xiantao Li

We make a detailed analysis of quantumness for various quantum noise channels, both Markovian and non-Markovian. The noise channels considered include dephasing channels like random telegraph noise, non-Markovian dephasing and phase…

Quantum Physics · Physics 2020-05-05 Javid Naikoo , Subhashish Banerjee