Polarization vs. magnetic field: competing eigenbases in laser-driven atoms

• URL: http://arxiv.org/abs/2310.18525v1
• Date: Fri, 27 Oct 2023 22:52:40 GMT
• Title: Polarization vs. magnetic field: competing eigenbases in laser-driven atoms
• Authors: Nicol\'as Adri\'an Nu\~nez Barreto, Cecilia Cormick, Christian Tom\'as Schmiegelow
• Abstract summary: In the absence of a magnetic field, the atom can get trapped in a dark state, which inhibits fluorescence. A canonical way to avoid optical pumping to dark states is to apply a magnetic field at an angle with respect to the polarization of the exciting light. This generates a competition of eigenbases which manifests as a crossover between two regimes dominated either by the laser or the magnetic field.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We present experimental results and a theoretical model that illustrate how competing eigenbases can determine the dynamics of a fluorescing atom. In the absence of a magnetic field, the atom can get trapped in a dark state, which inhibits fluorescence. In general, this will happen when the magnetic degeneracy of the ground state is greater than the one of the excited state. A canonical way to avoid optical pumping to dark states is to apply a magnetic field at an angle with respect to the polarization of the exciting light. This generates a competition of eigenbases which manifests as a crossover between two regimes dominated either by the laser or the magnetic field. We illustrate this crossover with fluorescence measurements on a single laser-cooled calcium ion in a Paul trap and find that it occurs at a critical laser intensity that is proportional to the external magnetic field. We contrast our results with numerical simulations of the atomic levels involved and also present a simple theoretical model that provides excellent agreement with experimental results and facilitates the understanding of the dynamics.

Related papers

• Searching Axion-like Dark Matter by Amplifying Weak Magnetic Field with Quantum Zeno effect [0.0]
  We theoretically propose amplifying the magnetic-field signal by using nuclear spins by the quantum Zeno effect (QZE) Our findings may provide valuable guidance for the design of experiments on establishing new constraints of dark matter and exotic interactions.
  arXiv  Detail & Related papers  (2025-02-19T03:09:11Z)
• Quantum optical scattering by macroscopic lossy objects: A general approach [55.2480439325792]
  We develop a general approach to describe the scattering of quantum light by a lossy macroscopic object placed in vacuum. We exploit the input-output relation to connect the output state of the field to the input one. We analyze the impact of the classical transmission and absorption dyadics on the transitions from ingoing to outgoing s-polariton.
  arXiv  Detail & Related papers  (2024-11-27T17:44:29Z)
• A Gallery of Soft Modes: Theory and Experiment at a Ferromagnetic Quantum Phase Transition [0.0]
  We examine the low-energy excitations in the vicinity of the quantum critical point in LiHoF$_4$, a physical realization of the Transverse Field Ising Model. Microwave spectroscopy in tunable loop-gap resonator structures identifies and characterizes the soft mode and higher-energy electronuclear states.
  arXiv  Detail & Related papers  (2024-08-07T02:27:00Z)
• Cavity-induced switching between Bell-state textures in a quantum dot [0.0]
  We show how a simple theoretical model of this interplay at resonance predicts complex but measurable effects. New polariton states emerge that combine spin, relative modes, and radiation. We uncover novel topological effects involving highly correlated spin and charge density.
  arXiv  Detail & Related papers  (2023-08-17T01:31:36Z)
• Thermal masses and trapped-ion quantum spin models: a self-consistent approach to Yukawa-type interactions in the $λ\!φ^4$ model [44.99833362998488]
  A quantum simulation of magnetism in trapped-ion systems makes use of the crystal vibrations to mediate pairwise interactions between spins. These interactions can be accounted for by a long-wavelength relativistic theory, where the phonons are described by a coarse-grained Klein-Gordon field. We show that thermal effects, which can be controlled by laser cooling, can unveil this flow through the appearance of thermal masses in interacting QFTs.
  arXiv  Detail & Related papers  (2023-05-10T12:59:07Z)
• Cavity-enhanced excitation of a quantum dot in the picosecond regime [0.4721851604275367]
  We investigate a scheme in which a single emitter, a semiconductor quantum dot, is embedded in a microcavity. By linking experiment to theory, we show that the best population inversion is achieved with a laser pulse detuned from the quantum emitter.
  arXiv  Detail & Related papers  (2023-01-31T17:47:57Z)
• Quantum density matrix theory for a laser without adiabatic elimination of the population inversion: transition to lasing in the class-B limit [62.997667081978825]
  No class-B quantum density-matrix model is available to date, capable of accurately describing coherence and photon correlations within a unified theory. Here we carry out a density-matrix theoretical approach for generic class-B lasers, and provide closed equations for the photonic and atomic reduced density matrix in the Fock basis of photons. This model enables the study of few-photon bifurcations and non-classical photon correlations in class-B laser devices, also leveraging quantum descriptions of coherently coupled nanolaser arrays.
  arXiv  Detail & Related papers  (2022-05-26T16:33:51Z)
• Dispersive readout of molecular spin qudits [68.8204255655161]
  We study the physics of a magnetic molecule described by a "giant" spin with multiple $d > 2$ spin states. We derive an expression for the output modes in the dispersive regime of operation. We find that the measurement of the cavity transmission allows to uniquely determine the spin state of the qudits.
  arXiv  Detail & Related papers  (2021-09-29T18:00:09Z)
• Trapping Effects in Quantum Atomic Arrays [5.623221917573403]
  We develop a microscopic quantum treatment using annihilation and creation operator of atoms in deep optical lattices. We apply our method to study the trapping effect, which is beyond previous treatment with spin operators.
  arXiv  Detail & Related papers  (2021-08-02T20:06:20Z)
• Photon-mediated interactions near a Dirac photonic crystal slab [68.8204255655161]
  We develop a theory of dipole radiation near photonic Dirac points in realistic structures. We find positions where the nature of the collective interactions change from being coherent to dissipative ones. Our results significantly improve the knowledge of Dirac light-matter interfaces.
  arXiv  Detail & Related papers  (2021-07-01T14:21:49Z)
• Spin Entanglement and Magnetic Competition via Long-range Interactions in Spinor Quantum Optical Lattices [62.997667081978825]
  We study the effects of cavity mediated long range magnetic interactions and optical lattices in ultracold matter. We find that global interactions modify the underlying magnetic character of the system while introducing competition scenarios. These allow new alternatives toward the design of robust mechanisms for quantum information purposes.
  arXiv  Detail & Related papers  (2020-11-16T08:03:44Z)

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.