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Related papers: Memory in quantum processes with indefinite time d…

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Compared to quantum logic gates, quantum memory has received far less attention. Here, we explore the prognosis for a solid-state, scalable quantum dynamic random access memory (Q-DRAM), where the qubits are encoded by the spin orientations…

Quantum Physics · Physics 2007-05-23 S. Bandyopadhyay

Quantum memories are key components of emerging quantum technologies. They are designed to store quantum states and retrieve them on demand without losing features such as superposition and entanglement. Verifying that a memory preserves…

In the last few years, there has been increasing interest in quantum processes with indefinite causal order. Process matrices are a convenient framework to study such processes. Ref. [1] defines higher order transformations from process…

Quantum Physics · Physics 2020-09-22 Esteban Castro-Ruiz , Flaminia Giacomini , Časlav Brukner

In standard quantum theory, the causal relations between operations are fixed. One can relax this notion by allowing for dynamical arrangements, where operations may influence the causal relations of future operations, as certified by…

Quantum Physics · Physics 2025-10-23 Veronika Baumann , Ämin Baumeler , Eleftherios-Ermis Tselentis

The duration, strength and structure of memory effects are crucial properties of physical evolution. Due to the invasive nature of quantum measurement, such properties must be defined with respect to the probing instruments employed. Here,…

Quantum Physics · Physics 2021-06-18 Yu Guo , Philip Taranto , Bi-Heng Liu , Xiao-Min Hu , Yun-Feng Huang , Chuan-Feng Li , Guang-Can Guo

We study the efficacy of the two recently introduced witnesses of non-Markovianity, namely that based on temporal correlations in pseudo-density matrix and temporal steering correlations in detecting information backflow. We show, through…

Quantum Physics · Physics 2025-07-01 Shrikant Utagi , Prateek Chawla

One of the defining traits of quantum mechanics is the uncertainty principle which was originally expressed in terms of the standard deviation of two observables. Alternatively, it can be formulated using entropic measures, and can also be…

Quantum Physics · Physics 2015-09-30 Göktuğ Karpat , Jyrki Piilo , Sabrina Maniscalco

The unavoidable finite time intervals between the sequential operations needed for performing practical quantum computing can degrade the performance of quantum computers. During these delays, unwanted relative dynamical phases are produced…

Quantum Physics · Physics 2009-11-10 L. F. Wei , Franco Nori

Indefinite causal order is a key feature involved in the study of quantum higher order transformations. Recently, intense research has been focused on possible advantages related to the lack of definite causal order of quantum processes.…

Quantum Physics · Physics 2023-06-12 Matheus Capela , Harshit Verma , Fabio Costa , Lucas Chibebe Céleri

Scrambling unitary dynamics in a quantum system transmutes local quantum information into a non-local web of correlations which manifests itself in a complex spatio-temporal pattern of entanglement. In such a context, we show there can…

Quantum Physics · Physics 2025-06-02 Alan Sherry , Sthitadhi Roy

Quantum supermaps are transformations that map quantum operations to quantum operations. It is known that quantum supermaps which respect a definite, predefined causal order between their input operations correspond to fixed-order quantum…

Quantum Physics · Physics 2023-06-21 Julian Wechs , Hippolyte Dourdent , Alastair A. Abbott , Cyril Branciard

We show that a quantum walk process can be used to construct and secure quantum memory. More precisely, we show that a localized quantum walk with temporal disorder can be engineered to store the information of a single, unknown qubit on a…

Quantum Physics · Physics 2015-04-22 C. M. Chandrashekar , Th. Busch

Standard measures of quantum non-Markovianity are usually defined in terms of dynamical maps on a preferred time foliation and therefore do not extend straightforwardly to curved spacetimes, where no global time coordinate exists and causal…

General Relativity and Quantum Cosmology · Physics 2026-02-04 Tushar Waghmare

Memory effects can be studied through a conditional past-future correlation, which measures departure with respect to a conditional past-future independence valid in a memoryless Markovian regime. In a quantum regime this property leads to…

Quantum Physics · Physics 2019-06-05 Adrian A. Budini

We use a Quantum Extreme Learning Machine for characterizing and estimating parameters of quantum dynamics generated by a tunable collision model. The input to the learning protocol consists of quantum states produced by successive system…

Quantum Physics · Physics 2026-03-19 Hajar Assil , Abderrahim El Allati , Gian Luca Giorgi

The problem of defining quantum non-Markovianity has proven elusive, with various in-equivalent criteria put forth to address it. The concept of CP-indivisibility and the hierarchy of stronger divisibility criteria going up to…

Quantum Physics · Physics 2020-09-15 Shrikant Utagi , R. Srikanth , Subhashish Banerjee

Quantum coherence is a prime resource in quantum computing and quantum communication. Quantum coherence of an arbitrary qubit state can be created at a remote location using maximally entangled state, local operation and classical…

Quantum Physics · Physics 2023-02-09 Jasleen Kaur , Shrobona Bagchi , Arun Kumar Pati

The definition of memory in operational approaches to quantum non-Markovianity depends on the statistical properties of different sets of outcomes related to successive measurement processes performed over the system of interest. Using…

Quantum Physics · Physics 2021-01-26 Mariano Bonifacio , Adrián A. Budini

We have investigated how memory effects on the teleportation of quantum Fisher information(QFI) for a single qubit system using a class of X-states as resources influenced by decoherence channels with memory, including amplitude damping,…

Quantum Physics · Physics 2020-01-08 Y. N. Guo , K. zeng , P. X. Chen

While spatial quantum correlations have been studied in great detail, much less is known about the genuine quantum correlations that can be exhibited by temporal processes. Employing the quantum comb formalism, processes in time can be…

Quantum Physics · Physics 2021-06-18 Simon Milz , Cornelia Spee , Zhen-Peng Xu , Felix A. Pollock , Kavan Modi , Otfried Gühne