The Study Of Quantum-classical Analogies In Classical Systems

The dynamics of waves plays an important role in solid state physics,atomic physics and acoustic physics.Despite the different natures of these waves,the corresponding evolution equations have the same mathematical form and hence wave phenomena can map to each other in different physical systems.The key idea behind the study of quantum-classical analogies is to reproduce the quantum mechanics of systems that are difficult to obtain by experimental means with other equivalent quantum or classical systems,thus providing better experimental control of relevant parameters.Sound and light waves are closely related to our life and are two important media for human beings to perceive and understand the world.Therefore,in acoustics and optics,it is necessary to study quantum mechanical phenomena of systems under different physical systems.In this paper,artificial microstructures are our research subject.Under acoustic and optical systems,these structures are designed to realize acoustic Bloch oscillation effect,Zeno effect,anti-Zeno effect and optically adjustable radiation enhancement.The study of these strange phenomena can not only reveal many interesting physical problems,but also provide a solid scientific basis for the research and development of novel quantum control devices.The main contents of this dissertation are as follows.1.Based on coupled mode theory,we study the Bloch oscillation effect in acoustic waveguide array.In order to effectively control the coupling of evanescent mode between adjacent waveguides,we firstly study the dispersion curves of single acoustic waveguide,and explore the relationship between structural parameters and propagation constants.In this context,we construct a structured waveguide array and get the BOs,which is the periodic propagation of sound waves in the acoustic waveguide array structure under the Wannier–Stark ladder(WSL)energy spectrum.Further,we also discuss the relationship between the variation of the BOs period and the width gradient.Finally,based on the theoretical predication,we observe experimentally the BO phenomenon,which is in agreement with the numerical results.This kind of structured waveguide array provides more freedom degrees for controlling the propagated and evanescent mode supported in waveguides,and provide a versatile test ground for simulating quantum effects in acoustic field.2.We construct waveguide array structure supporting spoof acoustic surface waves and report on the acoustic analogue of the quantum Zeno and quantum anti-Zeno control scheme.According to the characteristics of the waveguide,we construct waveguide arrays with boundary waveguides of different sizes and shapes.Than,we adjust the size of the boundary waveguide,the width of the boundary waveguide increases gradually.We can find that the decay rate of acoustic energy in the straight waveguide decreases gradually.Decay rate in the curved waveguide does not change dramatically.Our results generally indicate that adjustment for discrete to continuum interactions can either inhibit or accelerate its decay(the acoustic analogue of the quantum Zeno and quantum anti-Zeno).3.We design a two-dimensional curved acoustic topological insulator by perforating on a curved rigid plate,experimentally demonstrate that a topological localized state stands erect in bulk gap,and the corresponded pressure distributions are confined at the position with the maximal curvature.Introducing defects near the localized position,we also verify the robustness of topological localized state experimentally.The interplay between the geometrical curvature and the topology conception in the system,provides a novel scheme to manipulate and trap the waves propagation along the boundary of curved topological insulators,which may have potential applications in flexible devices.4.Spoof plasmonic cylinder structures with periodic grooves is designed in the deep-subwavelength scale,to control the direction and intensity of magnetic dipole emission in two-dimensional situations.By theoretical calculation and numerical simulation,we make an investigation of the resonant mechanism of the magnetic dipole in the spoof plasmonic structure.In this context,we also propose the array antenna,which is composed of three spoof plasmonic structures to realize directional magnetic dipole radiation with high intensity.These results indicate that the intensity of magnetic dipole emission is greatly enhanced,directional emission configuration is flexible.