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We consider the problem of reversing quantum dynamics, with the goal of preserving an initial state's quantum entanglement or classical correlation with a reference system. We exhibit an approximate reversal operation, adapted to the…

Quantum Physics · Physics 2026-01-21 H. Barnum , E. Knill

The task of compression of data -- as stated by the source coding theorem -- is one of the cornerstones of information theory. Data compression usually exploits statistical redundancies in the data according to its prior distribution.…

Quantum Physics · Physics 2021-01-08 Matheus Capela , Fabio Costa

We introduce a method to suppress unwanted transition channels, even without knowing their couplings, and achieve perfect population transfer in multistate quantum systems by the application of composite pulse sequences. Unwanted transition…

Quantum Physics · Physics 2015-06-11 Genko T. Genov , Nikolay V. Vitanov

Proposals for quantum computing devices are many and varied. They each have unique noise processes that make none of them fully reliable at this time. There are several error correction/avoidance techniques which are valuable for reducing…

Quantum Physics · Physics 2015-06-26 Mark S. Byrd , Daniel A. Lidar

This work presents a differentiable geometric parameterization of quantum channels in Kraus representation, which can be efficiently probed to find an unknown quantum channel. We explore its feasibility in finding the quasi inverse…

Quantum Physics · Physics 2025-12-02 Zain Ateeq , Muhammad Faryad

Refocusing of a quantum system in NMR and quantum information processing can be achieved by application of short pulses according to the methods of spin echo and dynamical decoupling. However, these methods are strongly limited by the…

Quantum Physics · Physics 2016-02-29 Imdad S. B. Sardharwalla , Toby S. Cubitt , Aram W. Harrow , Noah Linden

Single-photon wave packets can carry quantum information between nodes of a quantum network. An important general operation in photon-based quantum information systems is blind reversal of a photon's temporal wave-packet envelope, that is,…

Quantum Physics · Physics 2018-06-13 Michael G Raymer , Dileep V Reddy , Steven J van Enk , Colin J McKinstrie

The fundamental dynamics of quantum particles is neutral with respect to the arrow of time. And yet, our experiments are not: we observe quantum systems evolving from the past to the future, but not the other way round. A fundamental…

Quantum Physics · Physics 2022-11-01 Giulio Chiribella , Zixuan Liu

Quantum information scrambling is a unitary process that destroys local correlations and spreads information throughout the system, effectively hiding it in nonlocal degrees of freedom. In principle, unscrambling this information is…

Quantum Physics · Physics 2024-03-06 Salvatore F. E. Oliviero , Lorenzo Leone , Seth Lloyd , Alioscia Hamma

Simulating physical systems on quantum devices is one of the most promising applications of quantum technology. Current quantum approaches to simulating open quantum systems are still practically challenging on NISQ-era devices, because…

Quantum Physics · Physics 2024-09-09 Joseph Peetz , Scott E. Smart , Spyros Tserkis , Prineha Narang

Decoupling systems into independently evolving components has a long history of simplifying seemingly complex systems. They enable a better understanding of the underlying dynamics and causal structures while providing more efficient means…

Quantum Physics · Physics 2024-06-11 Ximing Wang , Chengran Yang , Mile Gu

The distribution of entangled quantum systems among two or more nodes of a network is a key task at the basis of quantum communication, quantum computation and quantum cryptography. Unfortunately the transmission lines used in this…

We investigate the problem of reversing quantum dynamics, specifically via optimal Petz recovery maps. We focus on typical decoherence channels, such as dephasing, depolarizing and amplitude damping. We illustrate how well a physically…

Quantum Physics · Physics 2022-05-06 Lea Lautenbacher , Fernando de Melo , Nadja K. Bernardes

Dephasing decoherence induced by interaction of one qubit with a quantum bath can be simulated classically by random unitary evolution without the need for a bath and this random unitary evolution is equivalent to the quantum case. For a…

Quantum Physics · Physics 2014-05-07 Daniel Crow , Robert Joynt

With the rapid developments in quantum hardware comes a push towards the first practical applications on these devices. While fully fault-tolerant quantum computers may still be years away, one may ask if there exist intermediate forms of…

Quantum Physics · Physics 2020-02-19 Jarrod R. McClean , Zhang Jiang , Nicholas C. Rubin , Ryan Babbush , Hartmut Neven

The Solovay-Kitaev theorem allows us to approximate any single-qubit gate to arbitrary accuracy with a finite sequence of fundamental operations from a universal set of gates. Inspired by this decomposition, we present a quantum channel…

A fully general strong converse for channel coding states that when the rate of sending classical information exceeds the capacity of a quantum channel, the probability of correctly decoding goes to zero exponentially in the number of…

Quantum Physics · Physics 2013-05-29 Robert Koenig , Stephanie Wehner

Blind Quantum Computation lets a limited-capability client delegate its complex computation to a remote server without revealing its data or computation. Several such protocols have been proposed under varied quantum computing models.…

Quantum Physics · Physics 2025-12-18 Mohit Joshi , Manoj Kumar Mishra , S. Karthikeyan

We define the direct and reverse secret-key capacities of a memoryless quantum channel as the optimal rates that entanglement-based quantum key distribution protocols can reach by using a single forward classical communication (direct…

Quantum Physics · Physics 2009-02-09 Stefano Pirandola , Raul Garcia-Patron , Samuel L. Braunstein , Seth Lloyd

Near-term quantum communication protocols suffer inevitably from channel noises, whose alleviation has been mostly attempted with resources such as multiparty entanglement or sophisticated experimental techniques. Generation of multiparty…

Quantum Physics · Physics 2023-02-21 Rajni Bala , Sooryansh Asthana , V. Ravishankar