Spatio-temporal properties of pulse propagation in a graphene quantum system

Laser Physics ◽  
2021 ◽  
Vol 32 (2) ◽  
pp. 025202
Author(s):  
Chao Xiao
Keyword(s):  
Quantum System ◽  
Light Propagation ◽  
Pulse Propagation ◽  
Quantum Information Processing ◽  
Dynamic Control ◽  
Optical Parameters ◽  
Temporal Properties ◽  
Time Domains ◽  
Potential Applications ◽  
Spatio Temporal

Abstract In this paper we have theoretically studied the spatial-temporal evolution of electromagnetic light propagation through a four-level graphene quantum system by using density matrix method and perturbation theory. The four-level graphene quantum medium interacted by an elliptical polarized coupling and a weak probe lights, respectively. We present the analytical solution for solving the Maxwell–Bloch equations for graphene and electromagnetic field in space and time domains. Then, we have analyzed the dynamic control of pulse propagation and optical dual switching in such a laser-driven quantum system. Our theoretical findings show that by adjusting the optical parameters such as elliptical angle i.e. phase difference between right-and-left circularly polarized, one can easily control the absorption spectrum and pulse propagation of the probe light in graphene medium. Our results may have potential applications in designing the new quantum devices for usage in quantum information processing.

scholarly journals A spatio-temporal specification language and its completeness & decidability

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Tengfei Li ◽  
Jing Liu ◽  
Haiying Sun ◽  
Xiang Chen ◽  
Lipeng Zhang ◽  
...  
Keyword(s):  
Intelligent Transportation System ◽  
Cyber Physical Systems ◽  
Specification Language ◽  
Finite Model ◽  
Critical Systems ◽  
Physical Systems ◽  
Spatial Objects ◽  
Temporal Properties ◽  
Spatio Temporal ◽  
Temporal Specification

AbstractIn the past few years, significant progress has been made on spatio-temporal cyber-physical systems in achieving spatio-temporal properties on several long-standing tasks. With the broader specification of spatio-temporal properties on various applications, the concerns over their spatio-temporal logics have been raised in public, especially after the widely reported safety-critical systems involving self-driving cars, intelligent transportation system, image processing. In this paper, we present a spatio-temporal specification language, STSL PC, by combining Signal Temporal Logic (STL) with a spatial logic S4 u, to characterize spatio-temporal dynamic behaviors of cyber-physical systems. This language is highly expressive: it allows the description of quantitative signals, by expressing spatio-temporal traces over real valued signals in dense time, and Boolean signals, by constraining values of spatial objects across threshold predicates. STSL PC combines the power of temporal modalities and spatial operators, and enjoys important properties such as finite model property. We provide a Hilbert-style axiomatization for the proposed STSL PC and prove the soundness and completeness by the spatio-temporal extension of maximal consistent set and canonical model. Further, we demonstrate the decidability of STSL PC and analyze the complexity of STSL PC. Besides, we generalize STSL to the evolution of spatial objects over time, called STSL OC, and provide the proof of its axiomatization system and decidability.

Spatio-temporal visual properties in the ascending tectofugal system

2010 ◽  
Vol 5 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Alice Rokszin ◽  
Zita Márkus ◽  
Gábor Braunitzer ◽  
Antal Berényi ◽  
Marek Wypych ◽  
...  
Keyword(s):  
Visual Information ◽  
Frequency Tuning ◽  
Temporal Frequency ◽  
Neuronal Population ◽  
Neuronal Responses ◽  
Temporal Properties ◽  
Visual Receptive Field ◽  
Detailed Statistical Analysis ◽  
Spatio Temporal ◽  
Visual Properties

AbstractOur study compares the spatio-temporal visual receptive field properties of different subcortical stages of the ascending tectofugal visual system. Extracellular single-cell recordings were performed in the superficial (SCs) and intermediate (SCi) layers of the superior colliculus (SC), the suprageniculate nucleus (Sg) of the posterior thalamus and the caudate nucleus (CN) of halothane-anesthetized cats. Neuronal responses to drifting gratings of various spatial and temporal frequencies were recorded. The neurons of each structure responded optimally to low spatial and high temporal frequencies and displayed narrow spatial and temporal frequency tuning. The detailed statistical analysis revealed that according to its stimulus preferences the SCs has markedly different spatio-temporal properties from the homogeneous group formed by the SCi, Sg and CN. The SCs neurons preferred higher spatial and lower temporal frequencies and had broader spatial tuning than the other structures. In contrast to the SCs the visually active SCi, as well as the Sg and the CN neurons possessed consequently similar spatio-temporal preferences. These data support our hypothesis that the visually active SCi, Sg and CN neurons form a homogeneous neuronal population given a similar spatio-temporal frequency preference and a common function in processing of dynamic visual information.

Spatio-temporal properties of oculomotor activation by multiple, simultaneous peripheral stimuli

2021 ◽  
Vol 188 ◽  
pp. 251-261
Author(s):  
John Christie ◽  
Matthew D. Hilchey ◽  
Raymond M. Klein
Keyword(s):  
Temporal Properties ◽  
Spatio Temporal

Sub-half-wavelength atom localization via two standing waves

2017 ◽  
Vol 95 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Haifeng Xu
Keyword(s):  
Quantum Interference ◽  
High Efficiency ◽  
Quantum Information Processing ◽  
One Dimensional ◽  
Half Wavelength ◽  
Potential Applications ◽  
Phase Gate ◽  
Quantum Error ◽  
Excited State Population ◽  
Atom Localization

We present a simple scheme of high-efficiency one-dimensional (1D) atom localization via manipulation of excited state population in a four-level inverted-Y atomic system. Because of the joint quantum interference induced by the two standing-wave fields, the 100% detecting probability of the atom in the subwavelength domain appears when the corresponding conditions are satisfied. The proposed scheme may open a promising way to achieve high-precision and high-efficiency 1D atom localization, which provides some potential applications to spatially selective single-qubit phase gate, entangling gates, and quantum error correction for quantum information processing.

scholarly journals Decomposing spatio-temporal seismicity patterns

2001 ◽  
Vol 1 (1/2) ◽  
pp. 83-92 ◽  
Author(s):  
C. Goltz
Keyword(s):  
Spatial And Temporal Variability ◽  
Seismicity Patterns ◽  
Seismicity Rate ◽  
Potential Applications ◽  
Time Series Approach ◽  
Distributed Process ◽  
Sample Application ◽  
Components Analysis ◽  
Spatio Temporal ◽  
Large Earthquakes

Abstract. Seismicity is a distributed process of great spatial and temporal variability and complexity. Efforts to characterise and describe the evolution of seismicity patterns have a long history. Today, the detection of changes in the spatial distribution of seismicity is still regarded as one of the most important approaches in monitoring and understanding seismicity. The problem of how to best describe these spatio-temporal changes remains, also in view of the detection of possible precursors for large earthquakes. In particular, it is difficult to separate the superimposed effects of different origin and to unveil the subtle (precursory) effects in the presence of stronger but irrelevant constituents. I present an approach to the latter two problems which relies on the Principal Components Analysis (PCA), a method based on eigen-structure analysis, by taking a time series approach and separating the seismicity rate patterns into a background component and components of change. I show a sample application to the Southern California area and discuss the promising results in view of their implications, potential applications and with respect to their possible precursory qualities.

THE TRAPPED-ION QUBIT: COHERENT CONTROL IN INFINITE-DIMENSIONAL QUANTUM SYSTEMS

2009 ◽  
Vol 24 (32) ◽  
pp. 2565-2578
Author(s):  
C. RANGAN
Keyword(s):  
Quantum Computing ◽  
Quantum System ◽  
Quantum Control ◽  
Coherent Control ◽  
Quantum Information Processing ◽  
Quantum Systems ◽  
Infinite Dimensional ◽  
Trapped Ion ◽  
Rich Variety ◽  
Control Research

Theories of quantum control have, until recently, made the assumption that the Hilbert space of a quantum system can be truncated to finite dimensions. Such truncations, which can be achieved for most quantum systems via bandwidth restrictions, have enabled the development of a rich variety of quantum control and optimal control schemes. Recent studies in quantum information processing have addressed the control of infinite-dimensional quantum systems such as the quantum states of a trapped-ion. Controllability in an infinite-dimensional quantum system is hard to prove with conventional methods, and infinite-dimensional systems provide unique challenges in designing control fields. In this paper, we will discuss the control of a popular system for quantum computing the trapped-ion qubit. This system, modeled by a spin-half particle coupled to a quantized harmonic oscillator, is an example for a surprisingly rich variety of control problems. We will show how this infinite-dimensional quantum system can be examined via the lens of the Finite Controllability Theorem, two-color STIRAP, the generalized Heisenberg system, etc. These results are important from the viewpoint of developing more efficient quantum control protocols, particularly in quantum computing systems. This work shows how one can expand the scope of quantum control research to beyond that of finite-dimensional quantum systems.

scholarly journals Near-Infrared Spatial Self-Phase Modulation in Ultrathin Niobium Carbide Nanosheets

2021 ◽  
Vol 9 ◽  
Author(s):  
Si Xiao ◽  
Yi-lin He ◽  
Yu-lan Dong ◽  
Yi-duo Wang ◽  
Li Zhou ◽  
...  
Keyword(s):  
Phase Modulation ◽  
Light Propagation ◽  
Near Infrared ◽  
Niobium Carbide ◽  
Infrared Region ◽  
Hybrid Structure ◽  
Optical Parameters ◽  
Self Phase Modulation ◽  
Non Linear ◽  
Linear Optical

Spatial self-phase modulation (SSPM) as a purely coherent non-linear optical effect (also known as Kerr effect) can support strong broadband phase modulation, which is essential for all-optical applications. Besides this, the increasing use of two-dimensional (2D) materials opens up new prospects in this field of research. In this work, we report a broadband SSPM response from 2D transition metal carbonitrides (MXenes) and Nb2C, arising in the near-infrared (1,550 nm) range. Based on the SSPM measurements of few-layer Nb2C nanosheets, the third-order non-linear optical parameters of Nb2C, including the non-linear refractive index n2 and susceptibility χ(3), were determined at 400, 800, 1,300, and 1,550 nm. Moreover, the physics mechanism of the dynamic formation process of SSPM diffraction rings was exploited. The formation time of SSPM diffraction rings can be divided into two typical parts which correspond to the polarization and reorientation of 2D Nb2C nanosheets. As a proof of concept, we demonstrate the nonreciprocal light propagation at wavelengths of 1,300 and 1,550 nm by constructing an Nb2C/water hybrid structure. Our results reveal strong optical phase modulation of Nb2C in the infrared region, thus showing the great potential of MXene materials for use in passive photonic devices.

Spatio-temporal properties of the pattern of evoked phantom sensations in a left index amputee patient.

1997 ◽  
Vol 111 (5) ◽  
pp. 867-872 ◽  
Author(s):  
Salvatore Aglioti ◽  
Nicola Smania ◽  
Andrea Atzei ◽  
Giovanni Berlucchi
Keyword(s):  
Temporal Properties ◽  
Spatio Temporal

Proposal for dimensionality testing in QPQ

2018 ◽  
Vol 18 (13&14) ◽  
pp. 1125-1142
Author(s):  
Arpita Maitra ◽  
Bibhas Adhikari ◽  
Satyabrata Adhikari
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum System ◽  
Quantum State ◽  
Quantum Information Processing ◽  
Quantum States ◽  
Quantum Private Query ◽  
Unfair Advantage ◽  
Security Proofs

Recently, dimensionality testing of a quantum state has received extensive attention (Ac{\'i}n et al. Phys. Rev. Letts. 2006, Scarani et al. Phys. Rev. Letts. 2006). Security proofs of existing quantum information processing protocols rely on the assumption about the dimension of quantum states in which logical bits are encoded. However, removing such assumption may cause security loophole. In the present paper, we show that this is indeed the case. We choose two players' quantum private query protocol by Yang et al. (Quant. Inf. Process. 2014) as an example and show how one player can gain an unfair advantage by changing the dimension of subsystem of a shared quantum system. To resist such attack we propose dimensionality testing in a different way. Our proposal is based on CHSH like game. As we exploit CHSH like game, it can be used to test if the states are product states for which the protocol becomes completely vulnerable.

scholarly journals Versatile Layer-By-Layer Highly Stable Multilayer Films: Study of the Loading and Release of FITC-Labeled Short Peptide in the Drug Delivery Field

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1206 ◽  
Author(s):  
Kun Nie ◽  
Xiang Yu ◽  
Navnita Kumar ◽  
Yihe Zhang
Keyword(s):  
Drug Delivery ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Multilayer Films ◽  
Layer By Layer ◽  
Guest Molecules ◽  
Potential Applications ◽  
Spatio Temporal ◽  
Release Speed

A viable short FITC-peptide immobilization is the most essential step in the fabrication of multilayer films based on FITC-peptide. These functional multilayer films have potential applications in drug delivery, medical therapy, and so forth. These FITC-peptides films needed to be handled with a lot of care and precision due to their sensitive nature. In this study, a general immobilization method is reported for the purpose of stabilizing various kinds of peptides at the interfacial regions. Utilizing Mesoporous silica nanoparticles can help in the preservation of these FITC-peptides by embedding themselves into these covalently cross-linked multilayers. This basic outlook of the multilayer films is potent enough and could be reused as a positive substrate. The spatio-temporal retention property of peptides can be modulated by varying the number of capping layers. The release speed of guest molecules such as tyrosine within FITC-peptide or/and adamantane (Ad)-in short peptides could also be fine-tuned by the specific arrangements of the multilayers of mesoporous silica nanoparticles (MSNs) and hyaluronic acid- cyclodextrin (HA-CD) multilayer films.

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