Quantum dynamics of large spins in static and rotating magnetic fields: Entanglement resonances and kinks
- URL: http://arxiv.org/abs/2510.26351v1
- Date: Thu, 30 Oct 2025 11:02:55 GMT
- Title: Quantum dynamics of large spins in static and rotating magnetic fields: Entanglement resonances and kinks
- Authors: Nargis Sultana, Siddharth Seetharaman, Rejish Nath,
- Abstract summary: We study the quantum dynamics of a large spin in the presence of static and rotating magnetic fields.<n>The dynamics exhibit periodic oscillations between two maximally stretched states, irrespective of how large the spin is.<n>We extend our analysis to a pair of spins, taking into account the dipole-dipole interactions between them.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We examine the quantum dynamics of a large spin in the presence of static and rotating magnetic fields. By mapping the system onto a gas of non-interacting spin-1/2 particles, we derive exact analytical results for the dynamics with different initial states. The dynamics exhibit periodic oscillations between two maximally stretched states, irrespective of how large the spin is. Further, we observe periodic transitions between sublevels with magnetic quantum numbers of opposite signs. Additionally, the dynamics features the periodic transfer of the spin to the maximally stretched state starting from a superposition state. The evolution of the dipole moment is also explored in each case, and as expected, it is precessing about the instantaneous, resultant magnetic field. Furthermore, we extend our analysis to a pair of spins, taking into account the dipole-dipole interactions between them. We analyze how the ground state entanglement between the spins depends on the external fields. The quantum dynamics of the two spins reveal entanglement resonances and kinks, which can be identified from the energy spectrum when weak transverse field strengths are considered. Finally, we discuss the regime in which the dipolar interactions are relatively weak.
Related papers
- Anomalous Trajectory Drift and Geometric Phases of Cyclic Spinor Solitons Induced by Virtual Magnetic Monopoles [8.63790768401275]
We investigate the dynamics of a two-component Bose-Einstein condensate with spin-orbit coupling numerically and analytically.<n>We observe that the system exhibits cyclic soliton motion; however, the trajectory of the soliton center shows a distinct drift.<n>The underlying mechanism of this anomalous drift is revealed: the moving soliton experiences a Lorentz force induced by a virtual magnetic monopole field in momentum space.
arXiv Detail & Related papers (2025-09-17T08:15:41Z) - 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.<n>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) - Super narrow peaks in excitation spectrum of alkali spin polarization: non-adiabatic case of spin dynamics [0.0]
Non-adiabatic spin dynamics occurs in a gas cell filled by alkali vapor.
S Steep increase of the spin polarization occurs if frequency of the magnetic field is equal to the certain value.
arXiv Detail & Related papers (2023-07-24T09:39:07Z) - Probing dynamics of a two-dimensional dipolar spin ensemble using single
qubit sensor [62.997667081978825]
We experimentally investigate individual spin dynamics in a two-dimensional ensemble of electron spins on the surface of a diamond crystal.
We show that this anomalously slow relaxation rate is due to the presence of strong dynamical disorder.
Our work paves the way towards microscopic study and control of quantum thermalization in strongly interacting disordered spin ensembles.
arXiv Detail & Related papers (2022-07-21T18:00:17Z) - Spreading of a local excitation in a Quantum Hierarchical Model [62.997667081978825]
We study the dynamics of the quantum Dyson hierarchical model in its paramagnetic phase.
An initial state made by a local excitation of the paramagnetic ground state is considered.
A localization mechanism is found and the excitation remains close to its initial position at arbitrary times.
arXiv Detail & Related papers (2022-07-14T10:05:20Z) - Dynamics of a Pair of Overlapping Polar Bright Solitons in Spin-1
Bose-Einstein Condensates [0.0]
We analyze the dynamics of both population and spin densities, emerging from the spatial overlap between two distinct polar bright solitons in Spin-1 Spinor Condensates.
The dynamics of final solitons depends explicitly on the relative phase.
arXiv Detail & Related papers (2022-04-29T13:33:38Z) - Understanding the propagation of excitations in quantum spin chains with
different kind of interactions [68.8204255655161]
It is shown that the inhomogeneous chains are able to transfer excitations with near perfect fidelity.
It is shown that both designed chains have in common a partially ordered spectrum and well localized eigenvectors.
arXiv Detail & Related papers (2021-12-31T15:09:48Z) - Anisotropic electron-nuclear interactions in a rotating quantum spin
bath [55.41644538483948]
Spin-bath interactions are strongly anisotropic, and rapid physical rotation has long been used in solid-state nuclear magnetic resonance.
We show that the interaction between electron spins of nitrogen-vacancy centers and a bath of $13$C nuclear spins introduces decoherence into the system.
Our findings offer new insights into the use of physical rotation for quantum control with implications for quantum systems having motional and rotational degrees of freedom that are not fixed.
arXiv Detail & Related papers (2021-05-16T06:15:00Z) - Quantum coherent spin-electric control in a molecular nanomagnet at
clock transitions [57.50861918173065]
Electrical control of spins at the nanoscale offers architectural advantages in spintronics.
Recent demonstrations of electric-field (E-field) sensitivities in molecular spin materials are tantalising.
E-field sensitivities reported so far are rather weak, prompting the question of how to design molecules with stronger spin-electric couplings.
arXiv Detail & Related papers (2020-05-03T09:27:31Z) - Effective dynamics for a spin-1/2 particle constrained to a space curve
in an electric and magnetic field [4.6145327012456425]
We consider the dynamics of a spin-1/2 particle constrained to move in an arbitrary space curve with an external electric and magnetic field applied.
With the aid of gauge theory, we successfully decouple the tangential and normal dynamics and derive the effective Hamiltonian.
A new type of quantum potential called SU(2) Zeeman interaction appears, which is induced by the electric field and couples spin and intrinsic orbital angular momentum.
arXiv Detail & Related papers (2020-02-12T10:03:26Z) - Spin current generation and control in carbon nanotubes by combining
rotation and magnetic field [78.72753218464803]
We study the quantum dynamics of ballistic electrons in rotating carbon nanotubes in the presence of a uniform magnetic field.
By suitably combining the applied magnetic field intensity and rotation speed, one can tune one of the currents to zero while keeping the other one finite, giving rise to a spin current generator.
arXiv Detail & Related papers (2020-01-20T08:54:56Z)
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.