Bounds on QCA Lattice Spacing from Data on Lorentz Violation

• URL: http://arxiv.org/abs/2506.20136v1
• Date: Wed, 25 Jun 2025 05:11:25 GMT
• Title: Bounds on QCA Lattice Spacing from Data on Lorentz Violation
• Authors: Leonard Mlodinow, Todd A. Brun,
• Abstract summary: Recent work has demonstrated that discrete quantum walks, when extended to quantum cellular automata (QCA), can reproduce relativistic wave equations and quantum field theories (QFTs)<n>This QCA/QFT correspondence bridges quantum information processing and high-energy physics, raising fundamental questions about the nature of spacetime.<n>We analyze the QCA corresponding to QED and show that it implies both a deviation from the speed of light and spatial anisotropies.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Recent work has demonstrated that discrete quantum walks, when extended to quantum cellular automata (QCA), can, in the continuum limit, reproduce relativistic wave equations and quantum field theories (QFTs), including free quantum electrodynamics (QED). This QCA/QFT correspondence bridges quantum information processing and high-energy physics, raising fundamental questions about the nature of spacetime: whether it is the continuum QFT or the discrete QCA that is fundamental. For while Lorentz invariance appears robust experimentally, it may only approximate a deeper discrete structure, particularly at Planck-scale energies. This high-energy Lorentz violation is potentially observable either through cumulative effects over cosmic distances or via small deviations at accessible energies. In this paper, we analyze the QCA corresponding to QED and show that it implies both a deviation from the speed of light and spatial anisotropies. Using current experimental and astrophysical constraints, we place upper bounds on the QCA lattice spacing, providing insight into the plausibility of a fundamentally discrete spacetime.

Related papers

• Topological control of quantum speed limits [55.2480439325792]
  We show that even if the quantum state is completely dispersionless, QFI in this state remains momentum-resolved.<n>We find bounds on quantum speed limit which scales as $sqrt|C|$ in a (dispersionless) topological phase.
  arXiv  Detail & Related papers  (2025-07-21T18:00:07Z)
• Reaching the Ultimate Quantum Precision Limit at Colliders: Conditions and Case Studies [15.086501264289614]
  We investigate whether collider experiments can reach the quantum limit of precision, defined by the quantum Fisher information (QFI)<n>We develop a general framework to determine when collider measurements can saturate the QFI in an entangled biparticle system.<n>We show that the classical Fisher informationally saturates the QFI for magnetic moments and CP-violating Higgs interactions in selected phase-space regions.
  arXiv  Detail & Related papers  (2025-06-12T13:03:36Z)
• Phase transitions, symmetries, and tunneling in Kerr parametric oscillators [37.69303106863453]
  We study the onset of ground-state and excited-state quantum phase transitions in KPOs.<n>We identify the critical points associated with quantum phase transitions and analyze their influence on the energy spectrum and tunneling dynamics.<n>Our findings provide insights into the engineering of robust quantum states, quantum dynamics control, and onset of quantum phase transitions with implications for critical quantum sensing.
  arXiv  Detail & Related papers  (2025-04-21T18:00:19Z)
• Many-body quantum geometry in time-dependent quantum systems with emergent quantum field theory instantaneously [13.437981636279718]
  We study many-body quantum geometric effects in time-dependent system with emergent quantum integrable field theory instantaneously.<n>Our results unveil telltale quantum geometric signatures in time-dependent many-body systems, elucidating the intricate interplay between quantum geometry and dynamics.
  arXiv  Detail & Related papers  (2025-03-24T07:09:04Z)
• Gravitational quantum speed limit [0.0]
  We find that the quantum mechanicalstam-Tamm and Margolus-Levitin bounds can be improved by superposing a spherically symmetric, static andally flat spacetime.<n>We discuss the feasibility and significance of measuring times via these superpositions.
  arXiv  Detail & Related papers  (2024-12-04T21:04:15Z)
• Increasing quantum speed limit via non-uniform magnetic field [1.7259860418331325]
  Quantum speed limit (QSL) defines the theoretical upper bound on how fast a quantum system can evolve between states.<n>We show that by using variable magnetic fields, it is possible to surpass this limit, achieving SQSL upto 0.4-0.6c.
  arXiv  Detail & Related papers  (2024-11-27T19:00:06Z)
• Bipartite Relativistic Quantum Information from Effective Field Theory Approach with Implications to Contextual Meanings of Locality and Quantumness [0.023020018305241332]
  We study the relativistic quantum information (RQI) of two static UDW-charged qubits with or without a black hole.<n>The RQI of the quantum state of the mediator field can be probed by the reduced final states of UDW detectors.<n>We find that QFT and RQI agree on quantumness based on different physical reasons but may not agree on locality.
  arXiv  Detail & Related papers  (2024-11-14T12:56:45Z)
• Quantum highway: Observation of minimal and maximal speed limits for few and many-body states [19.181412608418608]
  Inspired by the energy-time uncertainty principle, bounds have been demonstrated on the maximal speed at which a quantum state can change. We show that one can test the known quantum speed limits and that modifying a single Hamiltonian parameter allows the observation of the crossover of the different bounds on the dynamics.
  arXiv  Detail & Related papers  (2024-08-21T18:00:07Z)
• Boundary Time Crystals as AC sensors: enhancements and constraints [39.58317527488534]
  We find an enhanced sensitivity of the BTC when its spins are resonant with the applied AC field.<n>Despite its long coherence time and multipartite correlations, the entropic cost of the BTC hinders an optimal decoding of the AC field information.
  arXiv  Detail & Related papers  (2024-06-10T13:53:31Z)
• Quantum data learning for quantum simulations in high-energy physics [55.41644538483948]
  We explore the applicability of quantum-data learning to practical problems in high-energy physics. We make use of ansatz based on quantum convolutional neural networks and numerically show that it is capable of recognizing quantum phases of ground states. The observation of non-trivial learning properties demonstrated in these benchmarks will motivate further exploration of the quantum-data learning architecture in high-energy physics.
  arXiv  Detail & Related papers  (2023-06-29T18:00:01Z)
• Relativistic Particle Motion and Quantum Optics in a Weak Gravitational Field [0.0]
  Long-baseline quantum experiments in space make it necessary to better understand the time evolution of relativistic quantum particles in a weakly varying gravitational field. We explain why conventional treatments by traditional quantum optics and atomic physics may become inadequate when faced with issues related to locality, simultaneity, signaling, causality, etc. Adding the effects of gravitation, we are led to Quantum Field Theory in Curved Spacetime (QFTCST) This well-established theory should serve as the canonical reference theory to a large class of proposed space experiments testing the foundations of gravitation and quantum theory.
  arXiv  Detail & Related papers  (2021-06-23T16:32:45Z)
• Spacetime effects on wavepackets of coherent light [24.587462517914865]
  We introduce an operational way to distinguish between the overall shift in the pulse wavepacket and its genuine deformation after propagation. We then apply our technique to quantum states of photons that are coherent in the frequency degree of freedom. We find that the quantum coherence initially present can enhance the deformation induced by propagation in a curved background.
  arXiv  Detail & Related papers  (2021-06-23T14:20:19Z)
• Quantum simulation of open quantum systems in heavy-ion collisions [0.0]
  We present a framework to simulate the dynamics of hard probes such as heavy quarks or jets in a hot, strongly-coupled quark-gluon plasma (QGP) on a quantum computer. Our work demonstrates the feasibility of simulating open quantum systems on current and near-term quantum devices.
  arXiv  Detail & Related papers  (2020-10-07T18:00:02Z)
• Circuit Quantum Electrodynamics [62.997667081978825]
  Quantum mechanical effects at the macroscopic level were first explored in Josephson junction-based superconducting circuits in the 1980s. In the last twenty years, the emergence of quantum information science has intensified research toward using these circuits as qubits in quantum information processors. The field of circuit quantum electrodynamics (QED) has now become an independent and thriving field of research in its own right.
  arXiv  Detail & Related papers  (2020-05-26T12:47:38Z)

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.