Enhanced communication with the assistance of indefinite causal order
arXiv:1711.10165 · doi:10.1103/PhysRevLett.120.120502
Abstract
In quantum Shannon theory, the way information is encoded and decoded takes advantage of the laws of quantum mechanics, while the way communication channels are interlinked is assumed to be classical. In this Letter we relax the assumption that quantum channels are combined classically, showing that a quantum communication network where quantum channels are combined in a superposition of different orders can achieve tasks that are impossible in conventional quantum Shannon theory. In particular, we show that two identical copies of a completely depolarizing channel become able to transmit information when they are combined in a quantum superposition of two alternative orders. This finding runs counter to the intuition that if two communication channels are identical, using them in different orders should not make any difference. The failure of such intuition stems from the fact that a single noisy channel can be a random mixture of elementary, non-commuting processes, whose order (or lack thereof) can affect the ability to transmit information.
References in corpus (18)
- Quantum correlations with no causal order
- Entanglement-Assisted Classical Capacity of Noisy Quantum Channels
- Superadditivity of communication capacity using entangled inputs
- Quantum computations without definite causal structure
- Quantum Communication With Zero-Capacity Channels
- Experimental Superposition of Orders of Quantum Gates
- A mathematical theory of resources
- Experimental Verification of an Indefinite Causal Order
- Perfect discrimination of no-signalling channels via quantum superposition of causal structures
- Exponential Communication Complexity Advantage from Quantum Superposition of the Direction of Communication
- Causal and causally separable processes
- Quantum circuits cannot control unknown operations
- Implementing quantum control for unknown subroutines
- The quantum capacity with symmetric side channels
- Zero-error channel capacity and simulation assisted by non-local correlations
- "No Information Without Disturbance": Quantum Limitations of Measurement
- Coherent controlization using superconducting qubits
- No-Signalling Assisted Zero-Error Capacity of Quantum Channels and an Information Theoretic Interpretation of the Lovasz Number
Cited by in corpus (158)
- Indefinite Causal Order in a Quantum Switch
- Quantum Internet Protocol Stack: a Comprehensive Survey
- Quantum stochastic processes and quantum non-Markovian phenomena
- Quantum Metrology with Indefinite Causal Order
- Experimental transmission of quantum information using a superposition of causal orders
- Experimental Quantum Switching for Exponentially Superior Quantum Communication Complexity
- Quantum Refrigeration with Indefinite Causal Order
- Indefinite causal order enables perfect quantum communication with zero capacity channels
- Quantum Shannon theory with superpositions of trajectories
- Quantum Switch for the Quantum Internet: Noiseless Communications through Noisy Channels
- Experimental Quantum Communication Enhancement by Superposing Trajectories
- Communication through coherent control of quantum channels
- Communicating via ignorance: Increasing communication capacity via superposition of order
- Reversing Unknown Quantum Transformations: Universal Quantum Circuit for Inverting General Unitary Operations
- Tools for quantum network design
- Communication through quantum-controlled noise
- Time-delocalized quantum subsystems and operations: on the existence of processes with indefinite causal structure in quantum mechanics
- Resource theories of communication
- Communication Enhancement Through Quantum Coherent Control of Channels in an Indefinite Causal-order Scenario
- Quantum circuits with classical versus quantum control of causal order
- Sending classical information via three noisy channels in superposition of causal orders
- When entanglement harvesting is not really harvesting
- Cyclic Quantum Causal Models
- Experimentally feasible computational advantage from quantum superposition of gate orders
- Fundamental limitations on distillation of quantum channel resources
- Noisy quantum metrology with the assistance of indefinite causal order
- Work extraction from coherently activated maps via quantum switch
- Channel capacity enhancement with indefinite causal order
- Quantum Temporal Superposition: the case of QFT
- Probabilistic exact universal quantum circuits for transforming unitary operations
- Unruh-deWitt detectors in quantum superpositions of trajectories
- Quantum and Classical Data Transmission through Completely Depolarising Channels in a Superposition of Cyclic Orders
- Thermodynamic advancement in the causally inseparable occurrence of thermal maps
- Experiments on quantum causality
- On the definition and characterisation of multipartite causal (non)separability
- Complex Quantum Networks: a Topical Review
- Experimental Aspects of Indefinite Causal Order in Quantum Mechanics
- Why initial system-environment correlations do not imply the failure of complete positivity: a causal perspective
- Learning Temporal Quantum Tomography
- Memory effects in quantum metrology
- Thermal devices powered by generalized measurements with indefinite causal order
- Classical Communications with Indefinite Causal Order for completely depolarizing channels
- Superposition of causal order enables perfect quantum teleportation with very noisy singlets
- Beyond Shannon Limits: Quantum Communications through Quantum Paths
- Thermodynamics of quantum switch information capacity activation
- Causal order as a resource for quantum communication
- Random-Receiver Quantum Communication
- Steering-enhanced quantum metrology using superpositions of noisy phase shifts
- Indefinite causal order for quantum metrology with quantum thermal noise
- Quantum parameter estimation on coherently superposed noisy channels
- Symmetries of quantum evolutions
- Complex conjugation supermap of unitary quantum maps and its universal implementation protocol
- Quick charging of a quantum battery with superposed trajecotries
- Semi-device-independent certification of indefinite causal order in a photonic quantum switch
- Thermality, causality and the quantum-controlled Unruh-deWitt detector
- Higher-order Process Matrix Tomography of a passively-stable Quantum SWITCH
- Consequences of preserving reversibility in quantum superchannels
- Evading noise in multiparameter quantum metrology with indefinite causal order
- Enhancing Quantum Computation via Superposition of Quantum Gates
- Interferometric Approach to Open Quantum Systems and Non-Markovian Dynamics
- Superposed Quantum Error Mitigation
- Deterministic Generation of Multipartite Entanglement via Causal Activation in the Quantum Internet
- Controlled quantum operations and combs, and their applications to universal controllization of divisible unitary operations
- Fully-Optimized Quantum Metrology: Framework, Tools, and Applications
- Inferring the arrow of time in quantum spatiotemporal correlations
- Reassessing the advantage of indefinite causal orders for quantum metrology
- Reassessing thermodynamic advantage from indefinite causal order
- Quantum Uncertainty Principles for Measurements with Interventions
- Quantum causal correlations and non-Markovianity of quantum evolution
- Experimental demonstration of input-output indefiniteness in a single quantum device
- Simulating indefinite causal order with Rindler observers
- Quantum superpositions of causal orders as an operational resource
- Space-time dual quantum Zeno effect: Interferometric engineering of open quantum system dynamics
- Indefinite Causal Orders from Superpositions in Time
- Reassessing the computational advantage of quantum-controlled ordering of gates
- Necessary and Sufficient Conditions on Measurements of Quantum Channels
- Quantum communication through devices with indefinite input-output direction
- Unification of spatiotemporal quantum formalisms: mapping between process and pseudo-density matrices via multiple-time states
- Comparing the quantum switch and its simulations with energetically-constrained operations
- Postselected quantum hypothesis testing
- Experimental Validation of Enhanced Information Capacity by Quantum Switch in Accordance with Thermodynamic Laws
- Activating information backflow with the assistance of quantum SWITCH
- Maxwell's two-demon engine under pure dephasing noise
- Causal games of work extraction with indefinite causal order
- Experimentally demonstrating indefinite causal order algorithms to solve the generalized Deutsch's problem
- Classical communication through quantum causal structures
- Quantum communication using a quantum switch of quantum switches
- Breaking the limits of purification: Postselection enhances heat-bath algorithmic cooling
- Quantum switch instabilities with an open control
- Quantum networks boosted by entanglement with a control system
- Composition rules for quantum processes: a no-go theorem
- Memory in quantum processes with indefinite time direction and causal order
- Quantum superposition of causal structures as a universal resource for local implementation of nonlocal quantum operations
- Classical analogue of quantum superdense coding and communication advantage of a single quantum system
- Practical computational advantage from the quantum switch on a generalized family of promise problems
- The SWITCH test for discriminating quantum evolutions
- Activation of thermal states by coherently controlled thermalization processes
- Experimental Communication Through Superposition of Quantum Channels
- Quantum chicken-egg dilemmas: Delayed-choice causal order and the reality of causal non-separability
- A no-go theorem for superpositions of causal orders
- Using Quantum Switches to Mitigate Noise in Grover's Search Algorithm
- Compositional resource theories of coherence
- The quantum switch is uniquely defined by its action on unitary operations
- Quantum Supermaps are Characterized by Locality
- No-signalling constrains quantum computation with indefinite causal structure
- A Diagrammatic Approach to Information Transmission in Generalised Switches
- Building Multiple Access Channels with a Single Particle
- Interplay between the Hilbert-space dimension of a control system and the memory induced by a quantum SWITCH
- Indefinite causal order for quantum phase estimation with Pauli noise
- Network-Device-Independent Certification of Causal Nonseparability
- How Deep the Theory of Quantum Communications Goes: Superadditivity, Superactivation and Causal Activation
- Tsirelson bounds for quantum correlations with indefinite causal order
- Coherent control of the causal order of entanglement distillation
- Indefinite Time Directed Quantum Metrology
- Indefinite causal key distribution
- Quantifying Causal Influence in Quantum Mechanics
- Topics in Quantum Networking
- Universal quantum computation via quantum controlled classical operations
- Emergent non-Markovianity and dynamical quantification of the quantum switch
- Toward an Experimental Device-Independent Verification of Indefinite Causal Order
- Simulating violation of causality using a topological phase transition
- Recovery of damaged information via scrambling in indefinite casual order
- Background Independence and Quantum Causal Structure
- Error-free interconversion of nonlocal boxes
- Path superposition activating perfect quantum teleportation ability for separable states
- Expressibility, entangling power and quantum average causal effect for causally indefinite circuits
- Simulating the quantum switch with quantum circuits is computationally hard
- Multifold behavior of the information transmission by the quantum 3-switch
- Causality in Higher Order Process Theories
- Quantum theory cannot violate a causal inequality
- Quantum switch as a thermodynamic resource in the context of passive states
- Information Carried by a Single Particle in Quantum Multiple-Access Channels
- Quantum networks theory
- Remote Creation of Quantum Coherence via Indefinite Causal Order
- Tripartite non-classical correlations without backwards in time signalling
- Sequential device-independent certification of indefinite causal order
- Causal nonseparability and its implications for spatiotemporal relations
- To share and not share a singlet: control qubit and nonclassicality in teleportation
- Enhancement of non-Stabilizerness within Indefinite Causal Order
- Breaking absolute separability with quantum switch
- Thermodynamic criteria for signaling in quantum channels
- Optimal quantum precision in noise estimation: Is entanglement necessary?
- Quantum Paths: a Quantum Walk approach
- Signatures of causality and determinism in a quantum theory of events
- A Profunctorial Semantics for Quantum Supermaps
- Quantum Heat Transformers
- Error-Mitigated Multi-Layer Quantum Routing
- No quantum advantage for violating fixed-order inequalities?
- Distributed Quantum Dense Coding Enhanced With Non-classical Routing
- Refrigeration with Indefinite Causal Orders on a Cloud Quantum Computer
- Spatial Path Superposition: A No-Cloning Perspective on MIMO-Inspired Spatial Diversity
- Retrocausal capacity of a quantum channel: Communicating through noisy closed timelike curves
- Correlations in a quantum switch-based heat engine with measurements: A proof-of-principle demonstration
- Entropic uncertainty under indefinite causal order and input-output direction
- Optimal Thermalization under Indefinite Causal Order with Identical and Asymmetric Baths
- Quantum walks under superposition of causal order
- Information Exchange in Causally Nonseparable Processes
- Witnessing latent time correlations with a single quantum particle