We are now in the beginning of quantum supremacy to build Quantum Computers (Q.C.). So, a theoretical roadmap is required. It seems experimental works in Q.C. is ahead, in comparison with theory. In this study, Nano-Refraction (N.R.), as basic concept in developing Quantum Photonic Computers (Q.P.C.), is defined and discussed. N.R., is quite different from classical macroscopic refraction. It plays major role in photon deflection, when it travels in few atomic layers from the boundary between two transparent materials. Specifically, when we’re looking for a theoretically intuitive explanation of how advanced materials work in atomic scales in atto-second regime. To explain N.R., mathematically, Quantum Electrodynamics (QED) may help. But QED, only can describe how N.R. occurs in Hilbert space and does not explain why it happens in Real space? Why attosecond optical pulses are squeezed in kilometers long optical fibers coiled in first reported development of Q.C. in 2020. Also, “Duality” has no reply in this area. For answering why?, in this paper, we’ll use Quantum Photonic (Q.P.) theoretical analysis. Q.P., is based on Bohmian mechanics with intuition physics belief and “Causality”. Bohm theory in shadow of Quantum Mechanics (Q.M.) has been mostly ignored and even boycotted during last 70 years. Q.P. corpuscular viewpoint of light, estimated both physically and mathematically with enough precision, that flight route of photons at first few molecular surfaces in boundary region is not refracted suddenly. As can be observed macroscopically in Snell’s refraction equation. But instead, N.R. is happened gradually in attosecond regime (figure 2). Finally, it asymptotes to macroscopic refraction, in large space-time scales according to “correspondence” principle. Errors in our theoretical analysis using Montecarlo time domain simulation, compared with experiments, always are much less than or at most five percent.
We are now in the beginning of quantum supremacy to build Quantum Computers (Q.C.). So, a theoretical roadmap is required. It seems experimental works in Q.C. is ahead, in comparison with theory. In this study, Nano-Refraction (N.R.), as basic concept in developing Quantum Photonic Computers (Q.P.C.), is defined and discussed. N.R., is quite different from classical macroscopic refraction. It plays major role in photon deflection, when it travels in few atomic layers from the boundary between two transparent materials. Specifically, when we’re looking for a theoretically intuitive explanation of how advanced materials work in atomic scales in atto-second regime. To explain N.R., mathematically, Quantum Electrodynamics (QED) may help. But QED, only can describe how N.R. occurs in Hilbert space and does not explain why it happens in Real space? Why attosecond optical pulses are squeezed in kilometers long optical fibers coiled in first reported development of Q.C. in 2020. Also, “Duality” has no reply in this area. For answering why?, in this paper, we’ll use Quantum Photonic (Q.P.) theoretical analysis. Q.P., is based on Bohmian mechanics with intuition physics belief and “Causality”. Bohm theory in shadow of Quantum Mechanics (Q.M.) has been mostly ignored and even boycotted during last 70 years. Q.P. corpuscular viewpoint of light, estimated both physically and mathematically with enough precision, that flight route of photons at first few molecular surfaces in boundary region is not refracted suddenly. As can be observed macroscopically in Snell’s refraction equation. But instead, N.R. is happened gradually in attosecond regime (figure 2). Finally, it asymptotes to macroscopic refraction, in large space-time scales according to “correspondence” principle. Errors in our theoretical analysis using Montecarlo time domain simulation, compared with experiments, always are much less than or at most five percent.
Abstract Over the last few decades, the quantum aspects of light have been explored and major progress has been made in understanding the specific quantum aspects of the interaction between light and matter. Single photons are now routinely produced by single molecules on surfaces, vacancies in crystals, and quantum dots. The micrometre and nanometre scale is also the privileged range where fluctuations of electromagnetic fields manifest themselves through the Casimir force. The domain of classical optics has recently seen many exciting new developments, especially in the areas of nano-optics, nano-antennas, metamaterials, and optical cloaking. Approaches based on single-molecule detection and plasmonics have provided new avenues for exploring light–matter interaction at the nanometre scale. All these topics have in common a trend to consider and use smaller and smaller objects, down to the micrometre, nanometre, and even atomic range, a region where one gradually passes from classical physics to quantum physics. The summer school held in Les Houches in July 2013 treated all these subjects lying at the frontier between nanophotonics and quantum optics, in a series of lectures given by world experts in the domain and gathered together in the present volume.
Quantum phenomena are typically observable at length and time scales smaller than those of our everyday experience, often involving individual particles or excitations. The past few decades have seen a revolution in the ability to structure matter at the nanoscale, and experiments at the single particle level have become commonplace. This has opened wide new avenues for exploring and harnessing quantum mechanical effects in condensed matter. These quantum phenomena, in turn, have the potential to revolutionize the way we communicate, compute and probe the nanoscale world. Here, we review developments in key areas of quantum research in light of the nanotechnologies that enable them, with a view to what the future holds. Materials and devices with nanoscale features are used for quantum metrology and sensing, as building blocks for quantum computing, and as sources and detectors for quantum communication. They enable explorations of quantum behaviour and unconventional states in nano- and opto-mechanical systems, low-dimensional systems, molecular devices, nano-plasmonics, quantum electrodynamics, scanning tunnelling microscopy, and more. This rapidly expanding intersection of nanotechnology and quantum science/technology is mutually beneficial to both fields, laying claim to some of the most exciting scientific leaps of the last decade, with more on the horizon.
The past decade has seen an explosion of development in new devices, modalities, and architectures for advanced sensing, computation, and communication. This growth has been driven by the massive investments of large consumer-tech companies in data-hungry domains of customer interest. As these companies develop their products and seek a competitive edge, technologies which can provide advantage across application areas by making computation cheaper, or sensors more knowledgeable, or communication faster, are attracting more interest in and outside academia. Photonics, or the study of how to manipulate light, is a broad-based platform that inherently delivers on these promises. Although photonics has been a part of daily life since the invention of the laser, modern needs and aspirational designs which meet those needs far exceed the capabilities of the platforms which have traditionally constituted the photonics toolkit.\nThere are two specific areas where standard photonic materials are lacking - support for visible wavelengths and functionality for quantum optics. Currently, there are many implementations of systems which use visible light or quantum optics on the tabletop, but the drive to scale these technologies and deliver them to the consumer encounters a roadblock in their size and cost. Visible light sensors, for instance, could greatly benefit from conversion into an integrated photonics platform, where the optical components are printed onto a small substrate. However, the standard materials used for such systems (silicon and indium phosphide) absorb visible light, and other materials (like silicon nitride) do not have the attributes required for advanced functionality. More compellingly, there exist very few material platforms which can host the quantum defects required for next-generation technologies like quantum computation or secure communication.\nThe past decade has seen extensive research into an emerging material platform which can deliver on the ability to bring integrated visible photonics and quantum optics to the same chip - diamond. With a broad transparency region (from UV to the far infrared) and high refractive index, diamond makes an excellent material for run-of-the-mill photonic devices. More importantly, it harbors atom-like defects in its crystal lattice - the nitrogen-vacancy, silicon-vacancy, and germanium-vacancy centers, among many more - which provide a direct interface between the photons circulating within the diamond device and the quantum world. Taken together, these simple properties of diamond constitute a powerful approach towards implementation of advanced quantum technologies, such as repeaters for secure quantum communication or even, one day, computers.\nBefore that future arrives, diamond's capability must first be developed. Diamond has only been available in significant quantities for research use for about a decade, and as such, the processing technologies which are taken for granted in silicon or silicon nitride-based work must be redeveloped. Within the context of photonic devices, we discuss different fabrication strategies and their implications for device design. For visible light devices especially, we investigate methods to reduce sidewall roughness for etched structures.\nInterfacing with diamond photonic structures also brings its own unique set of challenges due to its high refractive index and very small material footprint. To this end, we develop a method termed "loaded tapered-fiber coupling" to optically access large, free-standing diamond devices. For size-limited diamond resonators and waveguides, we also develop auxiliary optical waveguides to act as spot-converters for visible wavelengths, an improvement on previous techniques for telecom-range wavelengths.\nFinally, by synthesizing these improvements in fabrication, we embark on a set of experiments in diamond microresonators. Nonlinear optics is an excellent testbed for such improvements, both for diamond's superlative properties in that regard and their high sensitivity to improvements in fabrication. First, we look at a process known as Raman lasing by constructing long path-length resonators.This technique involves the shifting of an input photon by 40 THz via the interaction with the diamond's crystal lattice.The first demonstration in a diamond integrated device was shown with a pump wavelength of 1600 nm, with an output that was tuned over 100 nm and a low threshold. Leveraging the developments in visible photonics for diamond, a second Raman laser was demonstrated, this time at near-visible (720 nm) wavelengths.This too had a Stokes output which was tunable to over 100 nm and a very low threshold. Raman-specific effects such as polarization conversion were also investigated.\nA cousin to the Raman effect, the Kerr nonlinearity plays a key role in so-called microresonator (or Kerr) frequency combs. We survey the possibilities and difficulties in implementation for a diamond platform, highlighting the competition between the Kerr and Raman nonlinearities. Although the outlook for a technologically relevant Kerr comb in diamond is ultimately pessimistic, avenues for improvement are highlighted. Namely, we investigate via simulation a related class of effects, known as supercontinuum generation.Taking advantage of subtleties of the Raman process in diamond, we can find a preferred geometry which enables generation of a broadband light spectrum natively in diamond.\nFinally, we look at alternative applications of diamond, particularly in high-power systems. Due to its excellent thermal conductivity and power-handling capacity, optics fashioned purely out of diamond can show significant advantages compared to other materials. We end with a discussion of the design principles and results stemming from this work.
The generalization of the quasi mode theory of macroscopic quantization in quantum optics and cavity QED presented in the previous paper, is applied to provide a fully quantum theoretic derivation of the laws of reflection and refraction at a boundary. The quasi mode picture of this process involves the annihilation of a photon travelling in the incident region quasi mode, and the subsequent creation of a photon in either the incident region or transmitted region quasi modes. The derivation of the laws of reflection and refraction is achieved through the dual application of the quasi mode theory and a quantum scattering theory based on the Heisenberg picture. Formal expressions from scattering theory are given for the reflection and transmission coefficients. The behaviour of the intensity for a localized one photon wave packet coming in at time minus infinity from the incident direction is examined and it is shown that at time plus infinity, the light intensity is only significant where the classical laws of reflection and refraction predict. The occurrence of both refraction and reflection is dependent upon the quasi mode theory coupling constants between incident and transmitted region quasi modes being non-zero, and it is seen that the contributions to such coupling constants come from the overlap of the mode functions in the boundary layer region, as might be expected from a microscopic theory.
The generalization of the quasi mode theory of macroscopic quantization in quantum optics and cavity QED presented in the previous paper, is applied to provide a fully quantum theoretic derivation of the laws of reflection and refraction at a boundary. The quasi mode picture of this process involves the annihilation of a photon travelling in the incident region quasi mode, and the subsequent creation of a photon in either the incident region or transmitted region quasi modes. The derivation of the laws of reflection and refraction is achieved through the dual application of the quasi mode theory and a quantum scattering theory based on the Heisenberg picture. Formal expressions from scattering theory are given for the reflection and transmission coefficients. The behaviour of the intensity for a localized one photon wave packet coming in at time minus infinity from the incident direction is examined and it is shown that at time plus infinity, the light intensity is only significant where the classical laws of reflection and refraction predict. The occurrence of both refraction and reflection is dependent upon the quasi mode theory coupling constants between incident and transmitted region quasi modes being nonzero, and it is seen that the contributions to such coupling constants come from the overlap of the mode functions in the boundary layer region, as might be expected from a microscopic theory.