Two quantum algorithms for communication between spacelike separated locations

• URL: http://arxiv.org/abs/2209.07741v1
• Date: Fri, 16 Sep 2022 06:54:22 GMT
• Title: Two quantum algorithms for communication between spacelike separated locations
• Authors: Amitava Datta
• Abstract summary: We argue that superluminal communication is possible through state discrimination in a higher-dimensional Hilbert space using ancilla qubits. We propose two quantum algorithms through state discrimantion for communication between two observers Alice and Bob.
• Score: 0.7614628596146599
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: The `no communication' theorem prohibits superluminal communication by showing that any measurement by Alice on an entangled system cannot change the reduced density matrix of Bob's state, and hence the expectation value of any measurement operator that Bob uses remains the same. We argue that the proof of the `no communication' theorem is incomplete and superluminal communication is possible through state discrimination in a higher-dimensional Hilbert space using ancilla qubits. We propose two quantum algorithms through state discrimantion for communication between two observers Alice and Bob, situated at spacelike separated locations. Alice and Bob share one qubit each of a Bell state $\frac{1}{\sqrt 2}(\ket{00}+\ket{11})$. While sending classical information, Alice measures her qubit and collapses the state of Bob's qubit in two different ways depending on whether she wants to send $0$ or $1$. Alice's first measurement is in the computational basis, and the second measurement is again in the computational basis after applying Hadamard transform to her qubit. Bob's first algorithm detects the classical bit with probability of error $<\frac{1}{2^k}$, but Alice and Bob need to share $k$ Bell states for communicating a single classical bit. Bob's second algorithm is more complex, but Bob can detect the classical bit deterministically using four ancilla qubits. We also discuss possible applications of our algorithms.

Related papers

• Multicopy quantum state teleportation with application to storage and retrieval of quantum programs [1.151731504874944]
  This work considers a teleportation task for Alice and Bob in a scenario where Bob cannot perform corrections. We show how the multicopy state teleportation protocol can be employed to enhance the success probability of storage and retrieval of quantum programs.
  arXiv  Detail & Related papers  (2024-09-16T15:30:36Z)
• Quantum advantage in a unified scenario and secure detection of resources [55.2480439325792]
  We consider a single task to study different approaches of having quantum advantage. We show that the optimal success probability in the overall process for a qubit communication might be higher than that for a cbit communication.
  arXiv  Detail & Related papers  (2023-09-22T23:06:20Z)
• Entanglement is better teleported than transmitted [0.0]
  We show that, for the purpose of quantum communication via a quantum field, it is essential to view the field as a source of entanglement. We present a protocol based on quantum teleportation in which Alice and Bob consume entanglement that they obtained from the field via interaction or harvesting.
  arXiv  Detail & Related papers  (2023-01-30T19:00:02Z)
• Identifying the value of a random variable unambiguously: Quantum versus classical approaches [44.99833362998488]
  Quantum resources may provide advantage over their classical counterparts. We construct such a task based on a game, mediated by Referee and played between Alice and Bob. We show that if Alice sends limited amount of classical information then the game cannot be won while the quantum analogue of the limited amount of classical information' is sufficient for winning the game.
  arXiv  Detail & Related papers  (2022-11-16T20:28:49Z)
• Proofs of Quantumness from Trapdoor Permutations [9.767030279324038]
  Alice and Bob communicate over only classical channels. Alice can do only classical probabilistic-time computing. Bob can be constructed from classically-secure (full-domain) trapdoor permutations.
  arXiv  Detail & Related papers  (2022-08-26T01:11:05Z)
• Entanglement and coherence in Bernstein-Vazirani algorithm [58.720142291102135]
  Bernstein-Vazirani algorithm allows one to determine a bit string encoded into an oracle. We analyze in detail the quantum resources in the Bernstein-Vazirani algorithm. We show that in the absence of entanglement, the performance of the algorithm is directly related to the amount of quantum coherence in the initial state.
  arXiv  Detail & Related papers  (2022-05-26T20:32:36Z)
• Quantum cryptography with classical communication: parallel remote state preparation for copy-protection, verification, and more [125.99533416395765]
  Many cryptographic primitives are two-party protocols, where one party, Bob, has full quantum computational capabilities, and the other party, Alice, is only required to send random BB84 states to Bob. We show how such protocols can generically be converted to ones where Alice is fully classical, assuming that Bob cannot efficiently solve the LWE problem. This means that all communication between (classical) Alice and (quantum) Bob is classical, yet they can still make use of cryptographic primitives that would be impossible if both parties were classical.
  arXiv  Detail & Related papers  (2022-01-31T18:56:31Z)
• Quantum secure direct communication with private dense coding using general preshared quantum state [59.99354397281036]
  We study secure direct communication by using a general preshared quantum state and a generalization of dense coding. For a practical application, we propose a concrete protocol and derive an upper bound of information leakage.
  arXiv  Detail & Related papers  (2021-12-30T16:12:07Z)
• Secure Two-Party Quantum Computation Over Classical Channels [63.97763079214294]
  We consider the setting where the two parties (a classical Alice and a quantum Bob) can communicate only via a classical channel. We show that it is in general impossible to realize a two-party quantum functionality with black-box simulation in the case of malicious quantum adversaries. We provide a compiler that takes as input a classical proof of quantum knowledge (PoQK) protocol for a QMA relation R and outputs a zero-knowledge PoQK for R that can be verified by classical parties.
  arXiv  Detail & Related papers  (2020-10-15T17:55:31Z)
• Arbitrarily many independent observers can share the nonlocality of a single maximally entangled qubit pair [4.061135251278187]
  We show that arbitrarily many independent Bobs can have an expected CHSH violation with the single Alice. Our work represents a step towards an eventual understanding of the limitations on how much device-independent randomness can be robustly generated from a single pair of qubits.
  arXiv  Detail & Related papers  (2020-03-26T18:38:56Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.