Dressed emitters as impurities

Abstract Dressed states forming when quantum emitters or atoms couple to a photonic bath underpin a number of phenomena and applications, in particular nonradiating effective interactions occurring within photonic bandgaps. Here, we present a compact formulation of the resolvent-based theory for calculating atom-photon dressed states built on the idea that the atom behaves as an effective impurity. This establishes an explicit connection with the standard impurity problem in condensed matter. Moreover, it allows us to formulate and settle – independently of the bath Hamiltonian – a number of properties previously known only for specific models or not entirely formalized. The framework is next extended to the case of more than one emitter, which is used to derive a general expression of dissipationless effective Hamiltonians explicitly featuring the overlap of single-emitter dressed bound states.

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Effective Interactions of Relativistic Composite Particles in Unified Nonlinear Spinor-Field Models. I

Zeitschrift für Naturforschung A ◽

10.1515/zna-1985-0105 ◽

1985 ◽

Vol 40 (1) ◽

pp. 14-28

Author(s):

H. Stumpf

Keyword(s):

Spinor Field ◽

Bound States ◽

Composite Particle ◽

Composite Particles ◽

Statistical Interpretation ◽

Particle Spectrum ◽

Nonlinear Spinor ◽

Effective Interactions ◽

Scattering States ◽

Diagonal Part

Unified nonlinear spinor field models are selfregularizing quantum field theories in which all observable (elementary and non-elementary) particles are assumed to be bound states of fermionic preon fields. Due to their large masses the preons themselves are confined. In preceding papers a functional energy representation, the statistical interpretation and the dynamical equations were derived. In this paper the dynamics of composite particles is discussed. The composite particles are defined to be eigensolutions of the diagonal part of the energy representation. Corresponding calculations are in preparation, but in the present paper a suitable composite particle spectrum is assumed. It consists of preon-antipreon boson states and threepreon- fermion states with corresponding antifermions and contains bound states as well as preon scattering states. The state functional is expanded in terms of these composite particle states with inclusion of preon scattering states. The transformation of the functional energy representation of the spinor field into composite particle functional operators produces a hierarchy of effective interactions at the composite particle level, the leading terms of which are identical with the functional energy representation of a phenomenological boson-fermion coupling theory. This representation is valid as long as the processes are assumed to be below the energetic threshold for preon production or preon break-up reactions, respectively. From this it can be concluded that below the threshold the effective interactions of composite particles in a unified spinor field model lead to phenomenological coupling theories which depend in their properties on the bound state spectrum of the self-regularizing spinor theory.

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FORMAL RELATION AMONG VARIOUS HERMITIAN AND NON-HERMITIAN EFFECTIVE INTERACTIONS

International Journal of Modern Physics E ◽

10.1142/s0218301305002734 ◽

2005 ◽

Vol 14 (01) ◽

pp. 21-28 ◽

Cited By ~ 4

Author(s):

RYOJI OKAMOTO ◽

SHINICHIRO FUJII ◽

KENJI SUZUKI

Keyword(s):

Effective Interaction ◽

Model Space ◽

General Definition ◽

Effective Interactions ◽

Formal Relation ◽

Definition Of ◽

Effective Hamiltonians

A general definition of the model-space effective interaction is given. The energy-independent effective Hamiltonians derived in a time-independent way are classified systematically.

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Electroweak Bosons, Leptons and Han-Nambu Quarks in a Unified Spinor-Isospinor Preon Field Model

Zeitschrift für Naturforschung A ◽

10.1515/zna-1986-1208 ◽

1986 ◽

Vol 41 (12) ◽

pp. 1399-1411

Author(s):

H. Stumpf

Keyword(s):

Shell Model ◽

Bound States ◽

First Generation ◽

Composite Fermions ◽

Energy Limit ◽

Mapping Procedure ◽

Effective Interactions ◽

Yang Mills ◽

Effective Dynamics ◽

Left Handed

The model is defined by a selfregularizing nonlinear spinor-isospinor preon field equation and all observable (elementary and non-elementary) particles are assumed to be bound states o f the quantized preon field. In a series o f preceding papers this model was extensively studied. In particular for com posite electroweak bosons the Yang-Mills dynamics was derived as the effective dynamics o f these bosons. In this paper the first generation o f com posite leptons and com posite Han-Nam bu quarks is introduced and together with electroweak bosons, these particles are interpreted as “shell model” states o f the underlying preon field. The choice o f the shell model states is justified by deriving the effective fermion-boson coupling and demonstrating its equivalence with the phenom enological electroweak coupling terms o f the Weinberg-Salam model. The investigation is restricted to the left-handed parts o f the composite fermions. Color is revealed to be a hidden orbital angular momentum in the shell model and hypercharge follows from the effective coupling. The techniques o f deriving effective interactions is a “weak mapping” procedure and the calculations are done in the “low” energy limit.

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Tunable and Robust Long-Range Coherent Interactions between Quantum Emitters Mediated by Weyl Bound States

Physical Review Letters ◽

10.1103/physrevlett.125.163602 ◽

2020 ◽

Vol 125 (16) ◽

Author(s):

Iñaki García-Elcano ◽

Alejandro González-Tudela ◽

Jorge Bravo-Abad

Keyword(s):

Long Range ◽

Bound States ◽

Quantum Emitters

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Evidence for dispersing 1D Majorana channels in an iron-based superconductor

Science ◽

10.1126/science.aaw8419 ◽

2020 ◽

Vol 367 (6473) ◽

pp. 104-108 ◽

Cited By ~ 10

Author(s):

Zhenyu Wang ◽

Jorge Olivares Rodriguez ◽

Lin Jiao ◽

Sean Howard ◽

Martin Graham ◽

...

Keyword(s):

Bound States ◽

Domain Walls ◽

Lattice Structure ◽

Condensed Matter ◽

One Dimension ◽

Scanning Tunneling ◽

Majorana Fermions ◽

Topological Phase ◽

Linear Dispersion ◽

Combined Data

The possible realization of Majorana fermions as quasiparticle excitations in condensed-matter physics has created much excitement. Most studies have focused on Majorana bound states; however, propagating Majorana states with linear dispersion have also been predicted. Here, we report scanning tunneling spectroscopic measurements of crystalline domain walls (DWs) in FeSe0.45Te0.55. We located DWs across which the lattice structure shifts by half a unit cell. These DWs have a finite, flat density of states inside the superconducting gap, which is a hallmark of linearly dispersing modes in one dimension. This signature is absent in DWs in the related superconductor, FeSe, which is not in the topological phase. Our combined data are consistent with the observation of dispersing Majorana states at a π-phase shift DW in a proximitized topological material.

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Bound states in screened and bare Coulomb potentials: A nonorthogonal CI-based route to effective Hamiltonians for two-electron systems

International Journal of Quantum Chemistry ◽

10.1002/(sici)1097-461x(1999)74:2<153::aid-qua12>3.0.co;2-8 ◽

1999 ◽

Vol 74 (2) ◽

pp. 153-161 ◽

Cited By ~ 4

Author(s):

Pinaki Chaudhury ◽

S. P. Bhattacharyya

Keyword(s):

Bound States ◽

Electron Systems ◽

Effective Hamiltonians ◽

Coulomb Potentials

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Condensates in quantum chromodynamics and the cosmological constant

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1010113107 ◽

2010 ◽

Vol 108 (1) ◽

pp. 45-50 ◽

Cited By ~ 78

Author(s):

Stanley J. Brodsky ◽

Robert Shrock

Keyword(s):

Cosmological Constant ◽

Quantum Chromodynamics ◽

Bound States ◽

Condensed Matter ◽

Chiral Symmetry Breaking ◽

De Sitter ◽

Conformal Field ◽

Color Confinement ◽

Gluon Condensates ◽

Hadron Masses

Casher and Susskind [Casher A, Susskind L (1974) Phys Rev 9:436–460] have noted that in the light-front description, spontaneous chiral symmetry breaking is a property of hadronic wavefunctions and not of the vacuum. Here we show from several physical perspectives that, because of color confinement, quark and gluon condensates in quantum chromodynamics (QCD) are associated with the internal dynamics of hadrons. We discuss condensates using condensed matter analogues, the Anti de Sitter/conformal field theory correspondence, and the Bethe–Salpeter–Dyson–Schwinger approach for bound states. Our analysis is in agreement with the Casher and Susskind model and the explicit demonstration of “in-hadron” condensates by Roberts and coworkers [Maris P, Roberts CD, Tandy PC (1998) Phys Lett B 420:267–273], using the Bethe–Salpeter–Dyson–Schwinger formalism for QCD-bound states. These results imply that QCD condensates give zero contribution to the cosmological constant, because all of the gravitational effects of the in-hadron condensates are already included in the normal contribution from hadron masses.

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Effective Interactions of Relativistic Composite Particles in Unified Nonlinear Spinor-Field Models. III

Zeitschrift für Naturforschung A ◽

10.1515/zna-1985-0315 ◽

1985 ◽

Vol 40 (3) ◽

pp. 294-302

Author(s):

H. Stumpf

Keyword(s):

Spinor Field ◽

Bound States ◽

Composite Particle ◽

Composite Particles ◽

Statistical Interpretation ◽

Particle Spectrum ◽

Nonlinear Spinor ◽

Effective Interactions ◽

Scattering States ◽

Diagonal Part

Unified nonlinear spinor field models are selfregularizing quantum field theories in which all observable (elementary and non-elementary) particles are assumed to be bound states of fermionic preon fields. Due to their large masses the preons themselves are confined. In preceding papers a functional energy representation, the statistical interpretation and the dynamic equations were derived. In this paper the dynamics of composite particles is discussed. The composite particles are defined to be eigensolutions of the diagonal part of the energy representation. Corresponding calculations are in preparation, but in the present paper a suitable composite particle spectrum is assumed. It consists of preon-antipreon boson states and threepreon- fermion states with corresponding antifermions and contains bound states as well as preon scattering states. The state functional is expanded in terms of these composite particle states with inclusion of preon scattering states. The transformation of the functional energy representation of the spinor field into composite particle functional operators produces a hierarchy of effective interactions at the composite particle level, the leading terms of which are identical with the functional energy representation of a phenomenological boson-fermion coupling theory. This representation is valid as long as the processes are assumed to be below the energetic threshold for preon production or preon break-up reactions, respectively. From this it can be concluded that below the threshold the effective interactions of composite particles in a unified spinor field model lead to phenomenological coupling theories which depend in their properties on the bound state spectrum of the self-regularizing spinor theory.

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