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Related papers: Qudit States in Noisy Quantum Channels

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We present a scalable method for learning local quantum channels using local expectation values measured on a single state -- their steady state. Our method is inspired by the algorithms for learning local Hamiltonians from their ground…

Quantum Physics · Physics 2024-07-12 Yigal Ilin , Itai Arad

We investigate the dynamics of quantum discord and entanglement for a class of mixed qubit-qutrit states assuming that only the qutrit is under the action of a dephasing channel. We demonstrate that even though the entanglement in the…

Quantum Physics · Physics 2013-04-02 G. Karpat , Z. Gedik

We present a systematic study of the phase-coherent dynamics of a superconducting three-Josephson-junction flux qubit. The qubit state is detected with the integrated-pulse method, which is a variant of the pulsed switching DC SQUID method.…

Superconductivity · Physics 2008-09-19 F. Deppe , M. Mariantoni , E. P. Menzel , S. Saito , K. Kakuyanagi , H. Tanaka , T. Meno , K. Semba , H. Takayanagi , R. Gross

In this paper we introduce a way to quantify the noise level associated to a given quantum transformation. The key mechanism lying at the heart of the proposal is "noise addition": in other words we compute the amount of extra noise we need…

Quantum Physics · Physics 2015-03-20 Antonella De Pasquale , Vittorio Giovannetti

In this work we study several models of decoherence and how different quantum maps and algorithms react when perturbed by them. Following closely Ref. [1], generalizations of the three paradigmatic one single qubit quantum channels (these…

Quantum Physics · Physics 2007-05-23 Mario Leandro Aolita , Marcos Saraceno

Quantum harmonic oscillators are central to many modern quantum technologies. We introduce a method to determine the frequency noise spectrum of oscillator modes through coupling them to a qubit with continuously driven…

Most previous efforts of quantum error correction focused on either extending classical error correction schemes to the quantum regime by performing a perfect correction on a subset of errors, or seeking a recovery operation to maximize the…

Quantum Physics · Physics 2023-09-06 Chengjie Zhang , Liangsheng Li , Guodong Lu , Haidong Yuan , Runyao Duan

A qubit (containing two quantum states, 1 and 2), is coupled to a control register (state 3), which is subject to telegraph noise. We study the time evolution of the density matrix $\rho$ of an electron which starts in some coherent state…

Mesoscale and Nanoscale Physics · Physics 2009-09-01 Amnon Aharony , Ora Entin-Wohlman , Sushanta Dattagupta

Quantum circuits implementing fault-tolerant quantum error correction (QEC) for the three qubit bit-flip code and five-qubit code are studied. To describe the effect of noise, we apply a model based on a generalized effective Hamiltonian…

Quantum Physics · Physics 2016-09-08 Y. C. Cheng , R. J. Silbey

Entanglement subject to noise can not be shielded against decaying. But, in case of many noisy channels, the degradation can be partially prevented by using local unitary operations. We consider the effect of local noise on shared quantum…

Quantum Physics · Physics 2025-02-05 Priya Ghosh , Kornikar Sen , Ujjwal Sen

Entanglement plays an indispensable role in numerous quantum information and quantum computation tasks, underscoring the need for efficiently verifying entangled states. In recent years, quantum state verification has received increasing…

Quantum Physics · Physics 2025-12-15 Lan Zhang , Yinfei Li , Ye-Chao Liu , Jiangwei Shang

We evaluate analytically the quantum discord for a large family of multiqubit states. It is interesting to note that the quantum discord of three-qubits and five-qubits is the same, as is the quantum discord of two-qubits and six-qubits. We…

Quantum Physics · Physics 2021-08-04 Bo Li , Chen-Lu Zhu , Xiao-Bin Liang , Biao-Liang Ye , Shao-Ming Fei

We investigate how noise impacts nonstabilizerness - a key resource for quantum advantage - in many-body qubit systems. While noise typically degrades quantum resources, we show that amplitude damping, a nonunital channel, can generate or…

Quantum Physics · Physics 2026-04-14 Fabian Ballar Trigueros , José Antonio Marín Guzmán

We show that two qubits, initially in a fully classical state, can develop significant quantum correlations as measured by the quantum discord (QD) under the action of a local memoryless noise (specifically we consider the case of a…

Quantum Physics · Physics 2012-02-10 Francesco Ciccarello , Vittorio Giovannetti

Connecting quantum computers to a quantum network opens a wide array of new applications, such as securely performing computations on distributed data sets. Near-term quantum networks are noisy, however, and hence correctness and security…

We consider dissipative dynamics of a flux qubit caused by 1/f noises, which act both on the shunting LC-contour and on the SQUID loop. These classical Gaussian noises modulate of the level splitting and of the tunnel coupling,…

Mesoscale and Nanoscale Physics · Physics 2018-07-25 F. T. Vasko

With the rapid advancement of Quantum Machine Learning (QML), the critical need to enhance security measures against adversarial attacks and protect QML models becomes increasingly evident. In this work, we outline the connection between…

Quantum Physics · Physics 2025-07-24 David Winderl , Nicola Franco , Jeanette Miriam Lorenz

The property of quantum correlation has been studied in recent years, especially for the quantum and classical correlations affected by environment. The dynamics of quantum and classical correlations in two-qubit system under identical…

Quantum Physics · Physics 2014-08-06 Bao-Cang Ren , Hai-Rui Wei , Fu-Guo Deng

Quantum noise fundamentally limits the utility of near-term quantum devices, making error mitigation essential for practical quantum computation. While traditional quantum error correction codes require substantial qubit overhead and…

Quantum Physics · Physics 2025-09-23 Karan Kendre

We investigate the effect of different types of non-unitary quantum channels on multi-qubit quantum systems. For an $n$-qubit system and a particular channel, in order to draw unbiased conclusions about the system as a whole as opposed to…

Quantum Physics · Physics 2020-05-07 Geetu Narang , Shruti Dogra , Arvind