Many Electrons and the Photon Field -- The many-body structure of nonrelativistic quantum electrodynamics

• URL: http://arxiv.org/abs/2102.11624v1
• Date: Tue, 23 Feb 2021 11:00:06 GMT
• Title: Many Electrons and the Photon Field -- The many-body structure of nonrelativistic quantum electrodynamics
• Authors: Florian Buchholz
• Abstract summary: We show how to turn electronic-structure methods into polaritonic-structure methods that are accurate from the weak to the strong-coupling regime. We discuss how to adopt standard algorithms of electronic-structure methods to adhere to the new hybrid Fermi-Bose statistics.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Recent experimental progress in the field of cavity quantum electrodynamics allows to study the regime of strong interaction between quantized light and complex matter systems. Due to the coherent coupling between photons and matter-degrees of freedom, polaritons -- hybrid light-matter quasiparticles -- emerge, which can significantly influence matter properties and complex processes such as chemical reactions (strong coupling). In this thesis we propose a way to overcome these problems by reformulating the coupled electron-photon problem in an exact way in a different, purpose-build Hilbert space, where no longer electrons and photons are the basic physical entities but the polaritons. Representing an N-electron-M-mode system by an N-polariton wave function with hybrid Fermi-Bose statistics, we show explicitly how to turn electronic-structure methods into polaritonic-structure methods that are accurate from the weak to the strong-coupling regime. We elucidate this paradigmatic shift by a comprehensive review of light-matter coupling, as well as by highlighting the connection between different electronic-structure methods and quantum-optical models. This extensive discussion accentuates that the polariton description is not only a mathematical trick, but it is grounded in a simple and intuitive physical argument: when the excitations of a system are hybrid entities a formulation of the theory in terms of these new entities is natural. Finally, we discuss in great detail how to adopt standard algorithms of electronic-structure methods to adhere to the new hybrid Fermi-Bose statistics. Guaranteeing the corresponding nonlinear inequality constraints in practice requires a careful development, implementation and validation of numerical algorithms. This extra numerical complexity is the price we pay for making the coupled matter-photon problem feasible for first-principle methods.

Related papers

• Light-Matter Hybridization and Entanglement from the First-Principles [3.8065968624597324]
  We introduce a variational Squeeze transformation capable of describing anharmonic quantum fluctuations in photon fields. This formalism enhances the description of light-matter Entanglement, providing a first-principles framework for understanding light-matter hybridization.
  arXiv  Detail & Related papers  (2024-11-22T15:52:50Z)
• Directional spontaneous emission in photonic crystal slabs [49.1574468325115]
  Spontaneous emission is a fundamental out-of-equilibrium process in which an excited quantum emitter relaxes to the ground state due to quantum fluctuations. One way to modify these photon-mediated interactions is to alter the dipole radiation patterns of the emitter, e.g., by placing photonic crystals near them. Our study delves into the interaction between these directional emission patterns and the aforementioned variables, revealing the untapped potential to fine-tune collective quantum optical phenomena.
  arXiv  Detail & Related papers  (2023-12-04T15:35:41Z)
• Simulating polaritonic ground states on noisy quantum devices [0.0]
  We introduce a general framework for simulating electron-photon coupled systems on small, noisy quantum devices. To achieve chemical accuracy, we exploit various symmetries in qubit reduction methods. We measure two properties: ground-state energy, fundamentally relevant to chemical reactivity, and photon number.
  arXiv  Detail & Related papers  (2023-10-03T14:45:54Z)
• Modeling Non-Covalent Interatomic Interactions on a Photonic Quantum Computer [50.24983453990065]
  We show that the cQDO model lends itself naturally to simulation on a photonic quantum computer. We calculate the binding energy curve of diatomic systems by leveraging Xanadu's Strawberry Fields photonics library. Remarkably, we find that two coupled bosonic QDOs exhibit a stable bond.
  arXiv  Detail & Related papers  (2023-06-14T14:44:12Z)
• Trapped-Ion Quantum Simulation of Collective Neutrino Oscillations [55.41644538483948]
  We study strategies to simulate the coherent collective oscillations of a system of N neutrinos in the two-flavor approximation using quantum computation. We find that the gate complexity using second order Trotter- Suzuki formulae scales better with system size than with other decomposition methods such as Quantum Signal Processing.
  arXiv  Detail & Related papers  (2022-07-07T09:39:40Z)
• Stochastic Variational Approach to Small Atoms and Molecules Coupled to Quantum Field Modes [55.41644538483948]
  We present a variational calculation (SVM) of energies and wave functions of few particle systems coupled to quantum fields in cavity QED. Examples for a two-dimensional trion and confined electrons as well as for the He atom and the Hydrogen molecule are presented.
  arXiv  Detail & Related papers  (2021-08-25T13:40:42Z)
• Nonperturbative Waveguide Quantum Electrodynamics [0.0]
  We study in and out of equilibrium properties of waveguide quantum electrodynamics. We uncover several surprising features ranging from symmetry-protected many-body bound states in the continuum to strong renormalization of the effective mass. Results are relevant to experiments in superconducting qubits interacting with microwave resonators or coupled atoms to photonic crystals.
  arXiv  Detail & Related papers  (2021-05-18T21:15:57Z)
• Waveguide quantum electrodynamics: collective radiance and photon-photon correlations [151.77380156599398]
  Quantum electrodynamics deals with the interaction of photons propagating in a waveguide with localized quantum emitters. We focus on guided photons and ordered arrays, leading to super- and sub-radiant states, bound photon states and quantum correlations with promising quantum information applications.
  arXiv  Detail & Related papers  (2021-03-11T17:49:52Z)
• Cavity Quantum Electrodynamics at Arbitrary Light-Matter Coupling Strengths [0.0]
  Quantum light-matter systems at strong coupling are notoriously challenging to analyze. We propose a nonperturbative approach to analyze light-matter correlations at all interaction strengths.
  arXiv  Detail & Related papers  (2020-10-07T18:00:10Z)
• Light-matter hybrid-orbital-based first-principles methods: the influence of the polariton statistics [0.0]
  We show the importance of the resulting hybrid Fermi-Bose statistics of the polaritons. We also present a general prescription how to extend a given first-principles approach to polaritons. We find that the more delocalized the bound-state wave function of the particles is, the stronger it reacts to photons.
  arXiv  Detail & Related papers  (2020-05-05T09:01:28Z)
• Theoretical methods for ultrastrong light-matter interactions [91.3755431537592]
  This article reviews theoretical methods developed to understand cavity quantum electrodynamics in the ultrastrong-coupling regime. The article gives a broad overview of the recent progress, ranging from analytical estimate of ground-state properties to proper computation of master equations. Most of the article is devoted to effective models, relevant for the various experimental platforms in which the ultrastrong coupling has been reached.
  arXiv  Detail & Related papers  (2020-01-23T18:09:10Z)

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.