English
Related papers

Related papers: Implementing Bell causality in Quantum Sequential …

200 papers

Bell scenarios are multipartite scenarios that exclude any signalling between parties. This leads to a strict hierarchy of classical, quantum, and non-signalling correlations in such scenarios. Here we consider a minimal relaxation of…

Quantum Physics · Physics 2025-07-01 Ravi Kunjwal , Ognyan Oreshkov

A size-extensive, converging, black-box, ab initio coupled-cluster ($\Delta$CC) ansatz is introduced that computes the energies and wave functions of stationary states from any degenerate or nondegenerate Slater-determinant references with…

Chemical Physics · Physics 2026-05-15 So Hirata

A classical precursor to a full quantum dynamics for causal sets has been forumlated in terms of a stochastic sequential growth process in which the elements of the causal set arise in a sort of accretion process. The transition…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Madhavan Varadarajan , David Rideout

Violation of the Bell-type inequalities is necessary to confirm the existence of nonlocality in nonclassical (entangled) states. We have designed a customized operator which is made of the sum of the Pauli matrices ($\sigma_x$, $\sigma_y$,…

Quantum Physics · Physics 2025-09-30 Tomis Prajapati , Harsh Mehta , Shreya Banerjee , Prasanta K. Panigrahi , V. Narayanan

This paper illustrates a direct connection between quantum steering and non-trivial preparation contextuality. In two party-two measurement per party-two outcomes per measurement $(2-2-2)$ Bell scenario, any argument of Bell nonlocality is…

Quantum Physics · Physics 2023-01-02 Prabuddha Roy , A. K. Pan

An obstacle affecting any proposal for a topological quantum computer based on Ising anyons is that quasiparticle braiding can only implement a finite (non-universal) set of quantum operations. The computational power of this restricted set…

Quantum Physics · Physics 2012-02-08 Mark Howard , Jiri Vala

The nature of quantum correlations in strongly correlated systems has been a subject of intense research. In particular, it has been realized that entanglement and quantum discord are present at quantum phase transitions and able to…

Quantum Physics · Physics 2014-01-03 Thiago R. de Oliveira , A. Saguia , M. S. Sarandy

Analyzing the geometry of correlation sets constrained by general causal structures is of paramount importance for foundational and quantum technology research. Addressing this task is generally challenging, prompting the development of…

The classic paper of Clauser et al proved that Bell's Theorem experiments rule out all theories of physics which assume locality, time-forwards causality and the existence of an objective real world. The Backwards-Time Interpretation (BTI)…

Quantum Physics · Physics 2007-05-23 Paul J. Werbos , Ludmila Dolmatova

In this work, we give rigorous operational meaning to superposition of causal orders. This fits within a recent effort to understand how the standard operational perspective on quantum theory could be extended to include indefinite…

Quantum Physics · Physics 2021-09-07 Nicola Pinzani , Stefano Gogioso

Logical consistency with free local operations is compatible with non-trivial classical communications, where all parties can be both in each other's past and future-a phenomenon known as noncausality. Noncausal processes, such as the…

Quantum Physics · Physics 2026-02-05 Anna Steffinlongo , Hippolyte Dourdent

Measurement-based quantum computation (MBQC) is a model of quantum computation, in which computation proceeds via adaptive single qubit measurements on a multi-qubit quantum state. It is computationally equivalent to the circuit model.…

Quantum processes with indefinite causal structure emerge when we wonder which are the most general evolutions, allowed by quantum theory, of a set of local systems which are not assumed to be in any particular causal order. These processes…

Quantum Physics · Physics 2024-02-07 Luca Apadula , Alessandro Bisio , Paolo Perinotti

Quantum Signal Processing (QSP) has emerged as a promising framework to manipulate and determine properties of quantum systems. QSP not only unifies most existing quantum algorithms but also provides tools to discover new ones. Quantum…

Quantum Physics · Physics 2023-09-12 V. M. Bastidas , S. Zeytinoğlu , Z. M. Rossi , I. L. Chuang , W. J. Munro

Analysis of quantum processes, especially in the context of noise, errors, and decoherence is essential for the improvement of quantum devices. An intuitive representation of those processes modeled by quantum channels are Pauli transfer…

Quantum Physics · Physics 2025-07-25 Lukas Hantzko , Lennart Binkowski , Sabhyata Gupta

In quantum physics the term `contextual' can be used in more than one way. One usage, here called `Bell contextual' since the idea goes back to Bell, is that if $A$, $B$ and $C$ are three quantum observables, with $A$ compatible (i.e.,…

Quantum Physics · Physics 2019-09-19 Robert B. Griffiths

Understanding the causal influences that hold among parts of a system is critical both to explaining that system's natural behaviour and to controlling it through targeted interventions. In a quantum world, understanding causal relations is…

Quantum Physics · Physics 2018-01-22 Jean-Philippe W. MacLean , Katja Ried , Robert W. Spekkens , Kevin J. Resch

A model master equation suitable for quantum computing dynamics is presented. In an ideal quantum computer (QC), a system of qubits evolves in time unitarily and, by virtue of their entanglement, interfere quantum mechanically to solve…

Quantum Physics · Physics 2017-05-31 Frank Tabakin

We introduce a formalism for the evaluation of counterfactual queries in the framework of quantum causal models, generalising Pearl's semantics for counterfactuals in classical causal models, thus completing the last rung in the quantum…

Quantum Physics · Physics 2024-09-18 Ardra Kooderi Suresh , Markus Frembs , Eric G. Cavalcanti

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