Quantum criticality under imperfect teleportation

• URL: http://arxiv.org/abs/2403.04843v2
• Date: Wed, 14 Aug 2024 04:51:29 GMT
• Title: Quantum criticality under imperfect teleportation
• Authors: Pablo Sala, Sara Murciano, Yue Liu, Jason Alicea,
• Abstract summary: Entanglement, measurement, and classical communication together enable teleportation of quantum states between distant parties. We show that imperfections in protocols effectively manifest as weak measurements acting on the otherwise pristinely teleported critical state. Results may allow one to design teleportation protocols that optimize against errors.
• Score: 6.839623159334513
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Entanglement, measurement, and classical communication together enable teleportation of quantum states between distant parties, in principle with perfect fidelity. To what extent do correlations and entanglement of a many-body wavefunction transfer under imperfect teleportation protocols? We address this question for the case of an imperfectly teleported quantum critical wavefunction, focusing on the ground state of a critical Ising chain. We demonstrate that imperfections, e.g., in the entangling gate adopted for a given protocol, effectively manifest as weak measurements acting on the otherwise pristinely teleported critical state. Armed with this perspective, we leverage and further develop the theory of measurement-altered quantum criticality to quantify the resilience of critical-state teleportation. We identify classes of teleportation protocols for which imperfection $(i)$ preserves both the universal long-range entanglement and correlations of the original quantum critical state, $(ii)$ weakly modifies these quantities away from their universal values, and $(iii)$ obliterates long-range entanglement altogether while preserving power-law correlations, albeit with a new set of exponents. We also show that mixed states describing the average over a series of sequential imperfect teleportation events retain pristine power-law correlations due to a `built-in' decoding algorithm, though their entanglement structure measured by the negativity depends on errors similarly to individual protocol runs. These results may allow one to design teleportation protocols that optimize against errors -- highlighting a potential practical application of measurement-altered criticality.

Related papers

• Uncorrectable-error-injection based reliable and secure quantum communication [0.0]
  Quantum teleportation is widely used to transmit arbitrary quantum states. It requires entanglement swapping and purification to distribute entanglements over long distances. These challenges limit its practicality for real-world quantum communication networks. We propose a novel scheme for directly transmitting quantum states encoded using error-correction codes.
  arXiv  Detail & Related papers  (2024-11-22T03:34:26Z)
• Macroscopic quantum teleportation with ensembles of qubits [10.017471827779337]
  We develop methods for performing quantum teleportation of the total spin variables of an unknown state. We introduce two protocols and show that, on average, the teleportation succeeds in teleporting the spin variables of a spin coherent state. A potential physical implementation for the scheme is with atomic ensembles and quantum nondemolition measurements performed with light.
  arXiv  Detail & Related papers  (2024-11-05T10:12:25Z)
• Finite temperature detection of quantum critical points via internal quantum teleportation [0.0]
  We show that the teleportation protocol can be efficiently used to detect quantum critical points using finite temperature data. Contrary to a previous proposal, there is no need to use an external qubit as the input state to be teleported to one of the qubits within the system.
  arXiv  Detail & Related papers  (2024-03-15T10:53:53Z)
• Robust teleportation of a surface code and cascade of topological quantum phase transitions [12.446931518819875]
  We investigate a protocol for teleporting a long-range entangled surface code state using elementary Bell measurements. We find infinitesimally weak entanglement is sufficient in teleporting a self-dual topological surface code. Our protocol, which can be readily implemented in dynamically Rydberg atom arrays, gives guidance for a practical demonstration of the power of quantum measurements.
  arXiv  Detail & Related papers  (2024-03-07T18:59:56Z)
• Dephasing effects on quantum correlations and teleportation in presence of state dependent bath [0.0]
  We analyze the effect of state dependent bath on the quantum correlations and the fidelity of a single qubit teleportation. It is shown that due to the presence of initial system-bath correlations, the system maintains quantum correlations for long times.
  arXiv  Detail & Related papers  (2023-07-03T15:31:19Z)
• Improved Quantum Algorithms for Fidelity Estimation [77.34726150561087]
  We develop new and efficient quantum algorithms for fidelity estimation with provable performance guarantees. Our algorithms use advanced quantum linear algebra techniques, such as the quantum singular value transformation. We prove that fidelity estimation to any non-trivial constant additive accuracy is hard in general.
  arXiv  Detail & Related papers  (2022-03-30T02:02:16Z)
• Experimental violations of Leggett-Garg's inequalities on a quantum computer [77.34726150561087]
  We experimentally observe the violations of Leggett-Garg-Bell's inequalities on single and multi-qubit systems. Our analysis highlights the limits of nowadays quantum platforms, showing that the above-mentioned correlation functions deviate from theoretical prediction as the number of qubits and the depth of the circuit grow.
  arXiv  Detail & Related papers  (2021-09-06T14:35:15Z)
• Hardware-Efficient, Fault-Tolerant Quantum Computation with Rydberg Atoms [55.41644538483948]
  We provide the first complete characterization of sources of error in a neutral-atom quantum computer. We develop a novel and distinctly efficient method to address the most important errors associated with the decay of atomic qubits to states outside of the computational subspace. Our protocols can be implemented in the near-term using state-of-the-art neutral atom platforms with qubits encoded in both alkali and alkaline-earth atoms.
  arXiv  Detail & Related papers  (2021-05-27T23:29:53Z)
• Direct Quantum Communications in the Presence of Realistic Noisy Entanglement [69.25543534545538]
  We propose a novel quantum communication scheme relying on realistic noisy pre-shared entanglement. Our performance analysis shows that the proposed scheme offers competitive QBER, yield, and goodput.
  arXiv  Detail & Related papers  (2020-12-22T13:06:12Z)
• Crosstalk Suppression for Fault-tolerant Quantum Error Correction with Trapped Ions [62.997667081978825]
  We present a study of crosstalk errors in a quantum-computing architecture based on a single string of ions confined by a radio-frequency trap, and manipulated by individually-addressed laser beams. This type of errors affects spectator qubits that, ideally, should remain unaltered during the application of single- and two-qubit quantum gates addressed at a different set of active qubits. We microscopically model crosstalk errors from first principles and present a detailed study showing the importance of using a coherent vs incoherent error modelling and, moreover, discuss strategies to actively suppress this crosstalk at the gate level.
  arXiv  Detail & Related papers  (2020-12-21T14:20:40Z)
• Fault-tolerant Coding for Quantum Communication [71.206200318454]
  encode and decode circuits to reliably send messages over many uses of a noisy channel. For every quantum channel $T$ and every $eps>0$ there exists a threshold $p(epsilon,T)$ for the gate error probability below which rates larger than $C-epsilon$ are fault-tolerantly achievable. Our results are relevant in communication over large distances, and also on-chip, where distant parts of a quantum computer might need to communicate under higher levels of noise.
  arXiv  Detail & Related papers  (2020-09-15T15:10:50Z)

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.