scholarly journals Time-delay polaritonics

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
J. D. Töpfer ◽  
H. Sigurdsson ◽  
L. Pickup ◽  
P. G. Lagoudakis
Keyword(s):  
Equations Of Motion ◽  
Signal Propagation ◽  
Matter Wave ◽  
Many Body ◽  
Coupled Equations ◽  
Exciton Polaritons ◽  
Non Linear ◽  
Linear Effects ◽  
Many Body Systems ◽  
Condensate System

AbstractNon-linearity and finite signal propagation speeds are omnipresent in nature, technologies, and real-world problems, where efficient ways of describing and predicting the effects of these elements are in high demand. Advances in engineering condensed matter systems, such as lattices of trapped condensates, have enabled studies on non-linear effects in many-body systems where exchange of particles between lattice nodes is effectively instantaneous. Here, we demonstrate a regime of macroscopic matter-wave systems, in which ballistically expanding condensates of microcavity exciton-polaritons act as picosecond, microscale non-linear oscillators subject to time-delayed interaction. The ease of optical control and readout of polariton condensates enables us to explore the phase space of two interacting condensates up to macroscopic distances highlighting its potential in extended configurations. We demonstrate deterministic tuning of the coupled-condensate system between fixed point and limit cycle regimes, which is fully reproduced by time-delayed coupled equations of motion similar to the Lang-Kobayashi equation.

THE UNIVERSAL EQUATIONS OF MOTION FOR NONLINEAR FIELDS IN DIFFERENT BASES DESCRIBING STRONGLY INTERACTING MANY-BODY SYSTEMS WITH TWO-BODY INTERACTIONS

1995 ◽  
Vol 09 (13n14) ◽  
pp. 1611-1637 ◽  
Author(s):  
J.M. DIXON ◽  
J.A. TUSZYŃSKI
Keyword(s):  
Plane Wave ◽  
Coherent Structures ◽  
Equations Of Motion ◽  
Quantum Field ◽  
Many Body ◽  
Field Equations ◽  
Strongly Interacting ◽  
Highly Nonlinear ◽  
Many Body Systems ◽  
Definition Of

A brief account of the Method of Coherent Structures (MCS) is presented using a plane-wave basis to define a quantum field. It is also demonstrated that the form of the quantum field equations, obtained by MCS, although highly nonlinear for many-body systems with two-body interactions, is independent of the basis of states used for the definition of the field.

Electronic Analogue Computer Study of Non-Linear Effects in a Class of Hydraulic Servomechanisms

1968 ◽  
Vol 10 (4) ◽  
pp. 346-359 ◽  
Author(s):  
J. Panjaby
Keyword(s):  
Coulomb Friction ◽  
Equations Of Motion ◽  
Control Valve ◽  
Static Friction ◽  
Analogue Computer ◽  
Prime Mover ◽  
Hydraulic Jack ◽  
Computer Study ◽  
Non Linear ◽  
Linear Effects

An electronic analogue is first described, of a system comprising a prime mover controlled by a non-linear flyweight governor using a non-linear hydraulic jack/valve servomechanism as a power amplifier to operate the prime mover energy supply control valve. The governor non-linearity is due to static and Coulomb friction. When dimensionless equations of motion are used for the various components in the system, the analogue is representative of a type of control system often encountered in mechanical engineering. It is shown that the presence of static friction in the governor, of magnitude greater than the Coulomb friction, has a de-stabilizing eifect and limit cycling of the system in the autonomous and non-autonomous conditions, caused by governor friction, is examined.

scholarly journals Landau–Zener Effect in Superfluid Nuclear Systems

2003 ◽  
Vol 18 (26) ◽  
pp. 1809-1817 ◽  
Author(s):  
M. Mirea
Keyword(s):  
Equations Of Motion ◽  
Deformation Energy ◽  
Cluster Decay ◽  
Many Body ◽  
Spectroscopic Factors ◽  
Nuclear Systems ◽  
Particle Level ◽  
Many Body Systems ◽  
Experimental Ratio ◽  
Good Agreement

The Landau–Zener effect is generalized for many-body systems with pairing residual interactions. The microscopic equations of motion are obtained and the 14C decay of 223Ra spectroscopic factors are deduced. An asymmetric nuclear shape parametrization given by two intersected spheres is used. The single particle level scheme is determined in the frame of the superasymmetric two-center shell model. The deformation energy is computed in the microscopic–macroscopic approximation. The penetrabilities are obtained within the WKB approximation. The fine structure of the cluster decay analyzed in the frame of this formalism gives a very good agreement with the experimental ratio of partial half-lives for transition to the first excited state and to the ground state.

scholarly journals Polaritons in an Electron Gas—Quasiparticles and Landau Effective Interactions

Atoms ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 81
Author(s):  
Miguel Angel Bastarrachea-Magnani ◽  
Jannie Thomsen ◽  
Arturo Camacho-Guardian ◽  
Georg M. Bruun
Keyword(s):  
Light Transmission ◽  
Landau Theory ◽  
Effective Interaction ◽  
Electron Gas ◽  
Ladder Approximation ◽  
Two Dimensional ◽  
Many Body ◽  
Strong Light ◽  
Exciton Polaritons ◽  
Many Body Systems

Two-dimensional semiconductors inside optical microcavities have emerged as a versatile platform to explore new hybrid light–matter quantum states. A strong light–matter coupling leads to the formation of exciton-polaritons, which in turn interact with the surrounding electron gas to form quasiparticles called polaron-polaritons. Here, we develop a general microscopic framework to calculate the properties of these quasiparticles, such as their energy and the interactions between them. From this, we give microscopic expressions for the parameters entering a Landau theory for the polaron-polaritons, which offers a simple yet powerful way to describe such interacting light–matter many-body systems. As an example of the application of our framework, we then use the ladder approximation to explore the properties of the polaron-polaritons. Furthermore, we show that they can be measured in a non-demolition way via the light transmission/reflection spectrum of the system. Finally, we demonstrate that the Landau effective interaction mediated by electron-hole excitations is attractive leading to red shifts of the polaron-polaritons. Our work provides a systematic framework to study exciton-polaritons in electronically doped two-dimensional materials such as novel van der Waals heterostructures.

A Derivation of Relativistically-Invariant Nonlinear Field Equations for Strongly Interacting Many-Body Systems

1997 ◽  
Vol 11 (07) ◽  
pp. 929-944 ◽  
Author(s):  
J. A. Tuszyński ◽  
J. M. Dixon
Keyword(s):  
Field Equation ◽  
Equations Of Motion ◽  
Nonlinear Field ◽  
Many Body ◽  
Field Equations ◽  
Strongly Interacting ◽  
Relativistic Regime ◽  
Klein Gordon ◽  
Many Body Systems ◽  
Nonlinear Field Equations

We re-examine the derivation of nonlinear field equations for a system of strongly interacting quasiparticles. Emphasis is placed on typical dispersion relations in the relativistic regime. Through Heisenberg's equations of motion for second-quantised operators we demonstrate that interacting many-body systems are described by a nonlinear Klein–Gordon type field equation. Its nonrelativistic equivalent was previously shown to be of the nonlinear Schrödinger type.

scholarly journals Correlations in high-harmonic generation of matter-wave jets revealed by pattern recognition

Science ◽  
2019 ◽  
Vol 363 (6426) ◽  
pp. 521-524 ◽  
Author(s):  
Lei Feng ◽  
Jiazhong Hu ◽  
Logan W. Clark ◽  
Cheng Chin
Keyword(s):  
Pattern Recognition ◽  
Harmonic Generation ◽  
Quantum Dynamics ◽  
High Harmonic ◽  
High Harmonic Generation ◽  
Einstein Condensate ◽  
Matter Wave ◽  
Many Body ◽  
Secondary Scattering ◽  
Many Body Systems

Correlations in interacting many-body systems are key to the study of quantum matter. The complexity of the correlations typically grows quickly as the system evolves and thus presents a challenge for experimental characterization and intuitive understanding. In a strongly driven Bose-Einstein condensate, we observe the high-harmonic generation of matter-wave jets with complex correlations as a result of bosonic stimulation. Based on a pattern recognition scheme, we identify a pattern of correlations that reveals the underlying secondary scattering processes and higher-order correlations. We show that pattern recognition offers a versatile strategy to visualize and analyze the quantum dynamics of a many-body system.

Sign in / Sign up

Export Citation Format

Share Document