Quantum tunneling and its absence in deep wells and strong magnetic fields
- URL: http://arxiv.org/abs/2412.21100v2
- Date: Tue, 31 Dec 2024 05:55:21 GMT
- Title: Quantum tunneling and its absence in deep wells and strong magnetic fields
- Authors: Charles L. Fefferman, Jacob Shapiro, Michael I. Weinstein,
- Abstract summary: We construct a family of double well potentials containing examples for which the low-energy eigenvalue splitting vanishes.<n>By deforming within this family, the magnetic ground state can be made to transition from symmetric to anti-symmetric.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: We present new results on quantum tunneling between deep potential wells, in the presence of a strong constant magnetic field. We construct a family of double well potentials containing examples for which the low-energy eigenvalue splitting vanishes, and hence quantum tunneling is eliminated. Further, by deforming within this family, the magnetic ground state can be made to transition from symmetric to anti-symmetric. However, for typical double wells in a certain regime, tunneling is not suppressed, and we provide a lower bound for the eigenvalue splitting.
Related papers
- Theory of the correlated quantum Zeno effect in a monitored qubit dimer [41.94295877935867]
We show how the competition between two measurement processes give rise to two distinct Quantum Zeno (QZ) regimes.
We develop a theory based on a Gutzwiller ansatz for the wavefunction that is able to capture the structure of the Hilbert phase diagram.
We show how the two QZ regimes are intimately connected to the topology of the flow of the underlying non-Hermitian Hamiltonian governing the no-click evolution.
arXiv Detail & Related papers (2025-03-28T19:44:48Z) - Controllable and Continuous Quantum Phase Transitions in Intrinsic Magnetic Topological Insulator [50.54133633499971]
We study the intrinsic magnetic topological material MnBi2Te4 in which the heavy n-type doping features are strongly suppressed.
Based on angle-resolved photoemission spectroscopy, transport measurements, and first-principles calculations, we reveal two magnetism-induced TPTs.
Our work paves the way for the realization of intrinsic magnetic topological states in MnBi2Te4 family and provides an ideal platform for achieving controllable and continuous TPTs.
arXiv Detail & Related papers (2025-03-08T03:46:54Z) - Harnessing Chiral Spin States in Molecular Nanomagnets for Quantum Technologies [44.1973928137492]
We show that chiral qubits naturally suppress always-on interactions that can not be switched off in weakly coupled qubits.
Our findings establish spin chirality engineering as a promising strategy for mitigating always-on interaction in entangling two chiral qubits in molecular quantum technologies.
arXiv Detail & Related papers (2025-01-21T08:23:12Z) - Oscillatory dissipative tunneling in an asymmetric double-well potential [32.65699367892846]
Chemical research will benefit from a fully adjustable, asymmetric double-well equipped with precise measurement capabilities of the tunneling rates.<n>We show a quantum simulator system that consists of a continuously driven Kerr parametric oscillator with a third order non-linearity that can be operated in the quantum regime to create a fully asymmetric double-well.<n>Our work is a first step for the development of analog molecule simulators of proton transfer reactions based on quantum superconducting circuits.
arXiv Detail & Related papers (2024-09-19T22:43:07Z) - Crossing exceptional points in non-Hermitian quantum systems [41.94295877935867]
We reveal the behavior of two-photon quantum states in non-Hermitian systems across the exceptional point.
We demonstrate a switching in the quantum interference of photons directly at the exceptional point.
arXiv Detail & Related papers (2024-07-17T14:04:00Z) - Edge modes and symmetry-protected topological states in open quantum
systems [0.0]
Topological order offers possibilities for processing quantum information which can be immune to imperfections.
We show robustness of certain aspects of $ZZtimes Z$ symmetry-protected trajectory (SPT) order against a wide class of dissipation channels.
Our work thus proposes a novel framework to study the dynamics of dissipative SPT phases.
arXiv Detail & Related papers (2023-10-13T21:09:52Z) - Fermion-parity qubit in a proximitized double quantum dot [0.0]
We encode quantum information in the local fermion parity of two tunnel-coupled quantum dots embedded in a Josephson junction.
At the sweet spot, the qubit states have zero charge dipole moment.
This protects the qubit from dephasing due to charge noise acting on the potential of each dot, as well as fluctuations of the (weak) inter-dot tunneling.
arXiv Detail & Related papers (2023-07-11T18:00:03Z) - Noise-resilient Edge Modes on a Chain of Superconducting Qubits [103.93329374521808]
Inherent symmetry of a quantum system may protect its otherwise fragile states.
We implement the one-dimensional kicked Ising model which exhibits non-local Majorana edge modes (MEMs) with $mathbbZ$ parity symmetry.
MEMs are found to be resilient against certain symmetry-breaking noise owing to a prethermalization mechanism.
arXiv Detail & Related papers (2022-04-24T22:34:15Z) - A strain-engineered graphene qubit in a nanobubble [0.0]
We propose a controllable qubit in a graphene nanobubble with emergent two-level systems induced by pseudo-magnetic fields.
We found that double quantum dots can be created by the strain-induced pseudo-magnetic fields of a nanobubble, and that their quantum states can be manipulated by either local gate potentials or the pseudo-magnetic fields.
arXiv Detail & Related papers (2021-11-24T03:29:24Z) - Dipole blockade without dipole-dipole interaction [3.6245152174496416]
We propose a novel physical mechanism for realizing dipole blockade without the dipole-dipole interaction.
Two qubits coupled to a cavity are driven by a coherent field.
We show that these two qubits are strongly entangled over a broad regime of the system parameters.
arXiv Detail & Related papers (2021-06-21T17:12:55Z) - Chemical tuning of spin clock transitions in molecular monomers based on
nuclear spin-free Ni(II) [52.259804540075514]
We report the existence of a sizeable quantum tunnelling splitting between the two lowest electronic spin levels of mononuclear Ni complexes.
The level anti-crossing, or magnetic clock transition, associated with this gap has been directly monitored by heat capacity experiments.
The comparison of these results with those obtained for a Co derivative, for which tunnelling is forbidden by symmetry, shows that the clock transition leads to an effective suppression of intermolecular spin-spin interactions.
arXiv Detail & Related papers (2021-03-04T13:31:40Z) - 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) - Lower Bound on Quantum Tunneling for Strong Magnetic Fields [0.0]
We consider a particle bound to a two-dimensional plane and a double well potential, subject to a perpendicular uniform magnetic field.
We obtain upper and lower bounds on this splitting in the regime where both the magnetic field strength and the depth of the wells are large.
arXiv Detail & Related papers (2020-06-14T21:12:03Z)
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.