scholarly journals Full waves, empty waves and subquantum processes

2020 ◽  
Author(s):  
Vladimir Skrebnev
Keyword(s):  
Beam Splitter ◽  
Single Photon ◽  
Single Photons ◽  
Absorption Coefficients ◽  
Empty Waves ◽  
Empty Wave

The appearance of a particle in a certain point in space, the full waves and the empty waves are considered as a consequence of subquantum processes. The experiment is described that measured the absorption of single photons by absorbers with various absorption coefficients, in one of the beams, after the photons interacted with the beam splitter. The measurements showed that the absorption corresponds to single photon traveling in either one or another beam. The results of our measurements and of single photon interference experiments, combined together, demonstrate the existence of the empty waves, that is, the excitations in the subquantum world, which do not contain a photon. We show that seemingly justified criticism of our interpretation of the experiment is not valid. New experiments are proposed to study single-photon interference involving an empty wave.

scholarly journals Experimental proof of the empty waves existence

2020 ◽  
Author(s):  
Vladimir Skrebnev
Keyword(s):  
Beam Splitter ◽  
Single Photon ◽  
Single Photons ◽  
Absorption Coefficients ◽  
Experimental Proof ◽  
Empty Waves ◽  
Empty Wave

The experiment measured the absorption of single photons by absorbers with various absorption coefficients, in one of the beams, after the photons interacted with the beam splitter. The measurements showed that the absorption corresponds to single photon traveling in either one or another beam. The results of our measurements and of single photon interference experiments, combined together, demonstrate the existence of the empty waves. We show that seemingly justified criticism of our interpretation of the experiment is not valid. New experiments are proposed to study single-photon interference involving an empty wave.

scholarly journals Quantum optics experiment on the test of empty wave hypothesis

2019 ◽  
Author(s):  
Vladimir Skrebnev
Keyword(s):  
Quantum Optics ◽  
Beam Splitter ◽  
Single Photon ◽  
Single Photons ◽  
Absorption Coefficients ◽  
Empty Wave

The experiment measured the absorption of single photons by absorbers with various absorption coefficients, in one of the beams, after the photons interacted with the beam splitter. The measurements showed that the absorption corresponds to single photon traveling in either one or another beam. The measurements support the original empty wave hypothesis which has been advanced in a number of works.

scholarly journals Phase estimation with squeezed single photons

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Stefano Olivares ◽  
Maria Popovic ◽  
Matteo G. A. Paris
Keyword(s):  
Coherent State ◽  
Fisher Information ◽  
Beam Splitter ◽  
Single Photon ◽  
Quantum Fisher Information ◽  
Single Photons ◽  
Squeezed Vacuum ◽  
Vacuum States ◽  
The Difference ◽  
Photocurrent Measurement

AbstractWe address the performance of an interferometric setup in which a squeezed single photon interferes at a beam splitter with a coherent state. Our analysis in based on both the quantum Fisher information and the sensitivity when a Mach-Zehnder setup is considered and the difference photocurrent is detected at the output. We compare our results with those obtained feeding the interferometer with a squeezed vacuum (with the same squeezing parameter of the squeezed single photon) and a coherent state in order to have the same total number of photons circulating in the interferometer. We find that for fixed squeezing parameter and total number of photons there is a threshold of the coherent amplitude interfering with the squeezed single photon above which the squeezed single photons outperform the performance of squeezed vacuum (showing the highest quantum Fisher information). When the difference photocurrent measurement is considered, we can always find a threshold of the squeezing parameter (given the total number of photons and the coherent amplitude) above which squeezed single photons can be exploited to reach a better sensitivity with respect to the use of squeezed vacuum states also in the presence of non unit quantum efficiency.

scholarly journals Single Photon Randomness based on a Defect Center in Diamond

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xing Chen ◽  
Johannes N. Greiner ◽  
Jörg Wrachtrup ◽  
Ilja Gerhardt
Keyword(s):  
Beam Splitter ◽  
Single Photon ◽  
Photon Emission ◽  
Random Number Generator ◽  
Input State ◽  
Single Photons ◽  
Ambient Conditions ◽  
Single Photon Detector ◽  
Defect Center ◽  
Random Bit Generator

AbstractThe prototype of a quantum random number generator is a single photon which impinges onto a beam splitter and is then detected by single photon detectors at one of the two output paths. Prior to detection, the photon is in a quantum mechanical superposition state of the two possible outcomes with –ideally– equal amplitudes until its position is determined by measurement. When the two output modes are observed by a single photon detector, the generated clicks can be interpreted as ones and zeros – and a raw random bit stream is obtained. Here we implement such a random bit generator based on single photons from a defect center in diamond. We investigate the single photon emission of the defect center by an anti-bunching measurement. This certifies the “quantumness” of the supplied photonic input state, while the random “decision” is still based on the vacuum fluctuations at the open port of the beam-splitter. Technical limitations, such as intensity fluctuations, mechanical drift, and bias are discussed. A number of ways to suppress such unwanted effects, and an a priori entropy estimation are presented. The single photon nature allows for a characterization of the non-classicality of the source, and allows to determine a background fraction. Due to the NV-center’s superior stability and optical properties, we can operate the generator under ambient conditions around the clock. We present a true 24/7 operation of the implemented random bit generator.

Realizable Single Photon Beam Splitter Based on Classical-Assisted Cyclic Transition of InGaAs/GaAs Quantum Dot Coupled to the T-Splitter Silver Nanowire

Plasmonics ◽  
2021 ◽  
Author(s):  
Myong-Chol Ko ◽  
Nam-Chol Kim ◽  
Su-Ryon Ri ◽  
Ju-Song Ryom ◽  
Song-Gun Kim ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Beam Splitter ◽  
Single Photon ◽  
Silver Nanowire ◽  
Photon Beam ◽  
Cyclic Transition ◽  
Gaas Quantum Dot

scholarly journals Quantum Structured Light: Non-classical Spin Texture of Twisted Single-photon Pulses

2021 ◽  
Author(s):  
Li-Ping Yang ◽  
Zubin Jacob
Keyword(s):  
Spin Density ◽  
Electromagnetic Waves ◽  
Single Photon ◽  
Structured Light ◽  
Three Dimensional ◽  
Quantum Spin ◽  
Single Photons ◽  
Spin Order ◽  
Spin Noise ◽  
Spin Texture

Abstract Classical structured light with controlled polarization and orbital angular momentum (OAM) of electromagnetic waves has varied applications in optical trapping, bio-sensing, optical communications and quantum simulations. The classical electromagnetic theory of such structured light beams and pulses have advanced significantly over the last two decades. However, a framework for the quantum density of spin and OAM for single-photons remains elusive. Here, we develop a theoretical framework and put forth the concept of quantum structured light for space-time wavepackets at the single-photon level. Our work marks a paradigm shift beyond scalar-field theory as well as the paraxial approximation and can be utilized to study the quantum properties of the spin and OAM of all classes of twisted quantum light pulses. We capture the uncertainty in full three-dimensional (3D) projections of vector spin demonstrating their quantum behavior beyond the conventional concept of classical polarization. Even in laser beams with high OAM along the propagation direction, we predict the existence of large OAM quantum fluctuations in the transverse plane which can be verified experimentally. We show that the spin density generates modulated helical texture beyond the paraxial limit and exhibits distinct statistics for Fock-state vs. coherent-state twisted pulses. We introduce the quantum correlator of photon spin density to characterize the nonlocal spin noise providing a rigorous parallel with fermionic spin noise operators. Our work paves the way for quantum spin-OAM physics in twisted single photon pulses and also opens explorations for new phases of light with long-range spin order.

Detection efficiency enhancement of single-photon detector at 1.55-μm by using of single photons lock-in and optimal threshold

2012 ◽  
Vol 44 (6) ◽  
pp. 1773-1775 ◽  
Author(s):  
Xiaobo Wang ◽  
Guofeng Zhang ◽  
Ruiyun Chen ◽  
Yan Gao ◽  
Liantuan Xiao ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Single Photon ◽  
Optimal Threshold ◽  
Single Photons ◽  
Efficiency Enhancement ◽  
Photon Detector ◽  
Single Photon Detector ◽  
Lock In

Automated Quantum Entanglement and Cryptography for Networks of Robotic Systems

2021 ◽  
Author(s):  
Farbod Khoshnoud ◽  
Maziar Ghazinejad
Keyword(s):  
Mobile Robots ◽  
Quantum Entanglement ◽  
Quantum Control ◽  
Single Photon ◽  
Autonomous Systems ◽  
Photon Counting ◽  
Robotic Systems ◽  
Single Photons ◽  
Alignment Procedure ◽  
Automated Alignment

Abstract In this paper the procedure for automating the photon quantum experiments for mobile robotic applications is presented. Due to the rapid advances of quantum technologies and quantum engineering, the integration of quantum capabilities in robotic and autonomous systems will be inevitable, and therefore the study and investigation of compatibility and adaptability of quantum systems and classical autonomous systems is of great importance. In a quantum-classical hybrid setup, the source of single photon generation is placed on a leader robot which can send correlated single photons to robot followers. In the case of quantum entanglement, spontaneous parametric down-conversion process using nonlinear paired BBO crystals is implemented which sends entangled photons to the single photon counting modules installed on mobile robots. In the case of quantum cryptography, single photons are sent from Alice robot to Bob robot, where Alice has the course of single photon and Bob has a polarizing beamsplitter and two detectors and that can detect the polarization of photons as vertical and horizontal. Bob then can convert the polarizations to a digital signals as zeros and ones and use them as communication information for control purposes through a classical channel. Motorized optics equipment can automatically align the source of photons to detectors on the mobile robots. The automated alignment procedure is one of the key enabling technologies in integrating quantum capabilities with control of mobile robotic systems. In this paper, in particular, the automated alignment is studied while considering the uncertainties in the dynamic of the system which can potentially cause the alignment task very challenging. The uncertainty analysis in the automated alignment is implemented by Optimal Uncertainty Quantification technique to ensure achieving the quantum control of the robotic systems and presented here for the first time.

scholarly journals Photon-Detection-Probability Simulation Method for CMOS Single-Photon Avalanche Diodes

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 436 ◽  
Author(s):  
Chin-An Hsieh ◽  
Chia-Ming Tsai ◽  
Bing-Yue Tsui ◽  
Bo-Jen Hsiao ◽  
Sheng-Di Lin
Keyword(s):  
Detection Probability ◽  
Single Photon ◽  
Cmos Technology ◽  
Oxide Semiconductor ◽  
Cmos Process ◽  
Single Photons ◽  
Photon Detection ◽  
Important Indicator ◽  
Avalanche Diodes ◽  
Single Photon Avalanche Diodes

Single-photon avalanche diodes (SPADs) in complementary metal-oxide-semiconductor (CMOS) technology have excellent timing resolution and are capable to detect single photons. The most important indicator for its sensitivity, photon-detection probability (PDP), defines the probability of a successful detection for a single incident photon. To optimize PDP is a cost- and time-consuming task due to the complicated and expensive CMOS process. In this work, we have developed a simulation procedure to predict the PDP without any fitting parameter. With the given process parameters, our method combines the process, the electrical, and the optical simulations in commercially available software and the calculation of breakdown trigger probability. The simulation results have been compared with the experimental data conducted in an 800-nm CMOS technology and obtained a good consistence at the wavelength longer than 600 nm. The possible reasons for the disagreement at the short wavelength have been discussed. Our work provides an effective way to optimize the PDP of a SPAD prior to its fabrication.

scholarly journals Chaotic Quantum Key Distribution

Cryptography ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 24
Author(s):  
Noah Cowper ◽  
Harry Shaw ◽  
David Thayer
Keyword(s):  
Quantum Computing ◽  
Quantum Key Distribution ◽  
Single Photon ◽  
Photon Emission ◽  
Key Distribution ◽  
Maximum Amount ◽  
Single Photons ◽  
Single Photon Emission ◽  
Amount Of Information ◽  
Communication Scheme

The ability to send information securely is a vital aspect of today’s society, and with the developments in quantum computing, new ways to communicate have to be researched. We explored a novel application of quantum key distribution (QKD) and synchronized chaos which was utilized to mask a transmitted message. This communication scheme is not hampered by the ability to send single photons and consequently is not vulnerable to number splitting attacks like other QKD schemes that rely on single photon emission. This was shown by an eavesdropper gaining a maximum amount of information on the key during the first setup and listening to the key reconciliation to gain more information. We proved that there is a maximum amount of information an eavesdropper can gain during the communication, and this is insufficient to decode the message.

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