# A no-summoning theorem in relativistic quantum theory

@article{Kent2011ANT, title={A no-summoning theorem in relativistic quantum theory}, author={Adrian Kent}, journal={Quantum Information Processing}, year={2011}, volume={12}, pages={1023-1032} }

Alice gives Bob an unknown localized physical state at some point P. At some point Q in the causal future of P, Alice will ask Bob for the state back. Bob knows this, but does not know at which point Q until the request is made. Bob can satisfy Alice’s summons, with arbitrarily short delay, for a quantum state in Galilean space-time or a classical state in Minkowski space-time. However, given an unknown quantum state in Minkowski space-time, he cannot generally fulfil her summons. This no…

## 45 Citations

### Unconstrained summoning for relativistic quantum information processing

- PhysicsPhysical Review A
- 2018

We define a summoning task to require propagating an unknown quantum state to a point in space-time belonging to a set determined by classical inputs at points in space-time. We consider the…

### Efficient code for relativistic quantum summoning

- Computer ScienceNew Journal of Physics
- 2018

A thorough mathematical framework for summoning quantum information in a relativistic system is developed and a protocol based on a Calderbank–Shor–Steane code is presented that decreases the space complexity for encoding by a factor of two compared to the previous best result and reduces the gate complexity from scaling as the cube to the square of the number of causal diamonds.

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This work answers the operational question of exactly when the information can be summoned to a set of spacetime points, showing how to do so efficiently using a combination of teleportation and codeword-stabilized quantum codes.

### Summoning, No-Signalling and Relativistic Bit Commitments

- Computer ScienceEntropy
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Bit commitment protocols and other cryptographic protocols based on the no-summoning theorem can thus be proven secure against some classes of post-quantum but non-signalling adversaries.

### Foundations of Quantum Mechanics

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Quantum mechanics is an extraordinarily successful scientific theory. But more than 100 years after it was first introduced, the interpretation of the theory remains controversial. This Element…

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- Computer Science, Physics
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A general framework for defining tasks within (special) relativistic quantum theory is described and illustrated with examples from relativist quantum cryptography and relativists distributed quantum computation.

### A Quantum Paradox of Choice and Purported Classical Analogues

- Philosophy
- 2015

We recently considered the task of summoning an unknown quantum state and proved necessary and sufficient conditions for Alice to be able to guarantee to complete the task when there may be several…

### Relativistic Quantum Communication

- Physics
- 2013

In this Ph.D. thesis, I investigate the communication abilities of non-inertial observers and the precision to which they can measure parametrized states.
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### Quantum information, Bell inequalities and the no-signalling principle

- Computer Science
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A new quantum information task is presented, the quantum information causality game, whose success probability is upper bounded by the new principle, and an optimal strategy to perform it combines the quantum teleportation and superdense coding protocols with a task that has classical inputs.

### Quantum tasks in holography

- Computer ScienceJournal of High Energy Physics
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The cryptographic and AdS/CFT approaches to completing asymptotic quantum tasks are studied and the efficiency with which they replace bulk classical geometry with boundary entanglement is considered.

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