Access to Klein Tunneling via Space-Time Modulation

• URL: http://arxiv.org/abs/2510.21154v2
• Date: Tue, 28 Oct 2025 01:55:27 GMT
• Title: Access to Klein Tunneling via Space-Time Modulation
• Authors: Furkan Ok, Amir Bahrami, Christophe Caloz,
• Abstract summary: We show that space-time modulation of electromagnetic potentials enables Klein tunneling far below the static threshold.<n>The associated reduction in energy thresholds suggests the potential for experimental realization using flying-focus fronts and relativistic electron beams.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We show that space-time modulation of electromagnetic potentials enables Klein tunneling far below the static threshold. The derived kinematics reveal oblique transitions that can connect opposite-energy continua without requiring their overlap, yielding a velocity-tunable Klein gap where transmission vanishes within a finite velocity window and reemerges beyond. The associated reduction in energy thresholds -- by up to four orders of magnitude -- suggests the potential for experimental realization using flying-focus fronts and relativistic electron beams.

Related papers

• Exponentially enhanced sensing through nonreciprocal light propagation [42.02177719060884]
  Non-reciprocal light propagation allows detecting small perturbations with a signal-to-noise ratio that scales exponentially with system size.<n>Our results open a new paradigm in non-Hermitian sensing, with potential applications in remote sensing including the optical readout of superconducting circuits.
  arXiv  Detail & Related papers  (2025-11-21T02:17:33Z)
• Gradient-Based Inverse Optimization of Atom-Chip Wire Currents for BEC Transport [0.0]
  Modulating wire currents to shift a magnetic trap along an atom chip enables smooth contact-free delivery of Bose-Einstein condensates but can deform the confinement profile causing heating and atom loss.<n>We introduce a fast simulation framework based on inverse optimization that computes a wire current schedule that transports the atoms and restores the trap geometry upon arrival.
  arXiv  Detail & Related papers  (2025-08-14T10:27:08Z)
• Streamline controlled rectification of supercurrent in thin-film asymmetric weak links [39.58317527488534]
  We study the supercurrent diode effect (SDE) in mesoscopic superconducting weak links formed by asymmetric Dayem bridges.<n>By implementing controlled geometric defects at the junction between the constriction and superconducting leads, we induce current crowding and disrupt spatial symmetry.<n>Our findings advocate for mesoscopic Dayem bridges as a flexible platform for designing and controlling superconducting diode functionalities.
  arXiv  Detail & Related papers  (2025-07-16T14:26:18Z)
• Chaotic fluctuations in a universal set of transmon qubit gates [37.69303106863453]
  Transmon qubits arise from the quantization of nonlinear resonators. Fast entangling gates, operating at speeds close to the so-called quantum speed limit, contain transient regimes where the dynamics indeed becomes partially chaotic for just two transmons.
  arXiv  Detail & Related papers  (2023-11-24T16:30:56Z)
• Uncovering anisotropic effects of electric high-moment dipoles on the tunneling current in $\delta$-layer tunnel junctions [0.0]
  Two distinct conductivity regimes exist in $delta$-layer tunnel junctions. In the low-bias regime with high-resistance tunneling mode dipole impurities of nearly all orientations and moments can alter the current. In the high-bias regime with low-resistivity only dipole defects with high moment and orientated in the direction to the electron tunneling direction can significantly affect the current.
  arXiv  Detail & Related papers  (2023-10-10T15:27:41Z)
• Space-time resolved quantum field approach to Klein tunneling dynamics across a finite barrier [0.0]
  We find that no particle actually tunnels through a finite supercritical barrier, even in the case of resonant tunneling. The transmission is instead mediated by modulations in pair production rates, at each edge of the barrier.
  arXiv  Detail & Related papers  (2022-05-30T14:13:15Z)
• Tuning long-range fermion-mediated interactions in cold-atom quantum simulators [68.8204255655161]
  Engineering long-range interactions in cold-atom quantum simulators can lead to exotic quantum many-body behavior. Here, we propose several tuning knobs, accessible in current experimental platforms, that allow to further control the range and shape of the mediated interactions.
  arXiv  Detail & Related papers  (2022-03-31T13:32:12Z)
• Slowing down light in a qubit metamaterial [98.00295925462214]
  superconducting circuits in the microwave domain still lack such devices. We demonstrate slowing down electromagnetic waves in a superconducting metamaterial composed of eight qubits coupled to a common waveguide. Our findings demonstrate high flexibility of superconducting circuits to realize custom band structures.
  arXiv  Detail & Related papers  (2022-02-14T20:55:10Z)
• Quantum interference in strong-field ionization by a linearly polarized laser pulse, and its relevance to tunnel exit time and momentum [0.0]
  We investigate the liberation of an atomic electron by a linearly polarized single-cycle near-infrared laser pulse having a peak intensity that ensures tunneling. Based on phase space analysis and energy distribution in the instantaneous potential, we reveal the importance of quantum interference between tunneling and over-the-barrier pathways of escape.
  arXiv  Detail & Related papers  (2021-03-23T17:20:59Z)
• Probing the coherence of solid-state qubits at avoided crossings [51.805457601192614]
  We study the quantum dynamics of paramagnetic defects interacting with a nuclear spin bath at avoided crossings. The proposed theoretical approach paves the way to designing the coherence properties of spin qubits from first principles.
  arXiv  Detail & Related papers  (2020-10-21T15:37:59Z)
• Speeding Up Particle Slowing using Shortcuts to Adiabaticity [0.0]
  Time-resolved laser pulses with periodically modified detunings address an ultranarrow electronic transition. We show the advantages that potentially arise when the excited state decay rate is small.
  arXiv  Detail & Related papers  (2020-07-14T01:17:54Z)
• Collective radiation from distant emitters [63.391402501241195]
  We show that the spectrum of the radiated field exhibits non-Markovian features such as linewidth broadening beyond standard superradiance. We discuss a proof-of-concept implementation of our results in a superconducting circuit platform.
  arXiv  Detail & Related papers  (2020-06-22T19:03:52Z)
• Zitterbewegung and Klein-tunneling phenomena for transient quantum waves [77.34726150561087]
  We show that the Zitterbewegung effect manifests itself as a series of quantum beats of the particle density in the long-time limit. We also find a time-domain where the particle density of the point source is governed by the propagation of a main wavefront. The relative positions of these wavefronts are used to investigate the time-delay of quantum waves in the Klein-tunneling regime.
  arXiv  Detail & Related papers  (2020-03-09T21:27:02Z)

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.