scholarly journals Observing momentum disturbance in double-slit “which-way” measurements

2019 ◽  
Vol 5 (6) ◽  
pp. eaav9547 ◽  
Author(s):  
Ya Xiao ◽  
Howard M. Wiseman ◽  
Jin-Shi Xu ◽  
Yaron Kedem ◽  
Chuan-Feng Li ◽  
...  
Keyword(s):  
Momentum Transfer ◽  
Quantitative Relation ◽  
Late Time ◽  
Single Photons ◽  
Momentum Change ◽  
Interference Fringes ◽  
Wave Particle Duality ◽  
Bohmian Trajectories ◽  
Double Slit

Making a “which-way” measurement (WWM) to identify which slit a particle goes through in a double-slit apparatus will reduce the visibility of interference fringes. There has been a long-standing controversy over whether this can be attributed to an uncontrollable momentum transfer. Here, by reconstructing the Bohmian trajectories of single photons, we experimentally obtain the distribution of momentum change. For our WWM, the change we see is not a momentum kick that occurs at the point of the WWM, but rather one that nonclassically accumulates during the propagation of the photons. We further confirm a quantitative relation between the loss of visibility consequent on a WWM and the total (late-time) momentum disturbance. Our results emphasize the role of the Bohmian momentum in giving an intuitive picture of wave-particle duality and complementarity.

scholarly journals Taming the Delayed Choice Quantum Eraser

Quanta ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 44-56 ◽  
Author(s):  
Johannes Fankhauser
Keyword(s):  
Photon Pair ◽  
Standard Quantum ◽  
Quantum Eraser ◽  
Delayed Choice ◽  
Interference Fringes ◽  
Signal Photon ◽  
Proper Account ◽  
Double Slit ◽  
De Broglie Bohm

I discuss the delayed choice quantum eraser experiment by drawing an analogy to a Bell-type measurement and giving a straightforward account in standard quantum mechanics. The delayed choice quantum eraser experiment turns out to resemble a Bell-type scenario in which the resolution of the paradox is rather trivial, and so there really is no mystery.  At first glance, the experiment suggests that measurements on one part of an entangled photon pair (the idler) can be employed to control whether the measurement outcome of the other part of the photon pair (the signal) produces interference fringes at a screen after being sent through a double slit. Significantly, the choice whether there is interference or not can be made long after the signal photon encounters the screen. The results of the experiment have been alleged to invoke some sort of backwards in time influence. I argue that this issue can be eliminated by taking into proper account the role of the signal photon. Likewise, in the de Broglie–Bohm picture the trajectories of the particle can be given a well-defined description at any instant of time during the experiment. Thus, it is again clear that there is no need to resort to any kind of backwards in time influence.Quanta 2019; 8: 44-56.

THE NOTHING THAT REALLY IS!

2016 ◽  
Vol 12 (1) ◽  
pp. 4172-4177
Author(s):  
Abdul Malek
Keyword(s):  
Quantum Dynamics ◽  
Theoretical Physics ◽  
Historical Evolution ◽  
Proper Understanding ◽  
Physical Universe ◽  
Wave Particle Duality ◽  
Negative Effect ◽  
Materialist Interpretation

The denial of the existence of contradiction is at the root of all idealism in epistemology and the cause for alienations.  This alienation has become a hindrance for the understanding of the nature and the historical evolution mathematics itself and its role as an instrument in the enquiry of the physical universe (1). A dialectical materialist approach incorporating  the role of the contradiction of the unity of the opposites, chance and necessity etc., can provide a proper understanding of the historical evolution of mathematics and  may ameliorate  the negative effect of the alienation in modern theoretical physics and cosmology. The dialectical view also offers a more plausible materialist interpretation of the bewildering wave-particle duality in quantum dynamics (2).

scholarly journals Monitoring dispersive samples with single photons: the role of frequency correlations

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Emanuele Roccia ◽  
Marco G. Genoni ◽  
Luca Mancino ◽  
Ilaria Gianani ◽  
Marco Barbieri ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Simultaneous Estimation ◽  
Single Photons ◽  
Estimation Scheme ◽  
Correlation Parameters ◽  
Two Parameters ◽  
Quantum Limits ◽  
Cramer Rao Bound ◽  
Down Conversion

AbstractThe physics that governs quantum monitoring may involve other degrees of freedom than the ones initialised and controlled for probing. In this context we address the simultaneous estimation of phase and dephasing characterizing a dispersive medium, and we explore the role of frequency correlations within a photon pair generated via parametric down-conversion, when used as a probe for the medium. We derive the ultimate quantum limits on the estimation of the two parameters, by calculating the corresponding quantum Cramér-Rao bound; we then consider a feasible estimation scheme, based on the measurement of Stokes operators, and address its absolute performances in terms of the correlation parameters, and, more fundamentally, of the role played by correlations in the simultaneous achievability of the quantum Cramér- Rao bounds for each of the two parameters.

scholarly journals Thrust Force Generated by Heaving Motion of a Plate: The Role of Vortex-Induced Force

2021 ◽  
Author(s):  
Kazuo Matsuuchi
Keyword(s):  
Vortex Shedding ◽  
Thrust Force ◽  
Unsteady Motion ◽  
Force Generation ◽  
Thrust Coefficient ◽  
Momentum Change ◽  
Vortex Element ◽  
Motion Characteristics ◽  
Vortex Systems

To understand the force acting on birds, insects, and fish, we take heaving motion as a simple example. This motion might deviate from the real one. However, since the mechanism of force generation is the vortex shedding due to the motion of an object, the heaving motion is important for understanding the force generated by unsteady motion. The vortices released from the object are closely related to the motion characteristics. To understand the force acting on an object, information about momentum change is necessary. However, in vortex systems, it is impossible to estimate the usual momentum. Instead of the momentum, the “virtual momentum,” or the impulse, is needed to generate the force. For calculating the virtual momentum, we traced all vortices over a whole period, which was carried out by using the vortex-element method. The force was then calculated based on the information on the vortices. We derived the thrust coefficient as a function of the ratio of the heaving to travelling velocity.

scholarly journals A Study of the Magneto?Kerr and Other Effects at a Plasma Surface

1967 ◽  
Vol 20 (1) ◽  
pp. 29 ◽  
Author(s):  
LC Robinson
Keyword(s):  
Momentum Transfer ◽  
Kerr Effect ◽  
Collision Frequency ◽  
Absolute Measurement ◽  
High Electron ◽  
Surface Phenomena ◽  
Density Region ◽  
Plasma Surface ◽  
Microwave Reflection

The role of microwave reflection observations and particularly the magneto. microwave Kerr effect in the study of plasma surface phenomena is discussed. The method makes possible the absolute measurement of high electron surface densities in a density region not readily accessible to other experimental techniques, and it gives an indication of the collision frequency for momentum transfer.

scholarly journals K0SΣ0 photoproduction at the BGO-OD experiment

2020 ◽  
Vol 241 ◽  
pp. 01009
Author(s):  
Katrin Kohl ◽  
Stefan Alef ◽  
Patrick Bauer ◽  
Reinhard Beck ◽  
Alessandro Braghieri ◽  
...  
Keyword(s):  
Vector Meson ◽  
Momentum Transfer ◽  
Cross Section ◽  
Photon Beam ◽  
Bremsstrahlung Photon ◽  
Meson Photoproduction ◽  
Accelerator Facility ◽  
Transfer Processes

The BGO-OD experiment at the ELSA accelerator facility uses an energy tagged bremsstrahlung photon beam to investigate the excitation structure of the nucleon via meson photoproduction. The setup with a BGO calorimeter surrounding the target and an open dipole spectrometer covering the for ward region is ideally suited for investigating low momentum transfer processes, in particular in strangeness photoproduction. The associated photoproduction of K0S and hyperons is essential to understand the role of K* exchange mech anisms. A cusp-like structure observed in the yp → K0SΣ+ reaction at the K* threshold is described by models including dynamically generated resonances from vector meson-baryon interactions. Such interactions are pre dicted to give a peak like structure in K0SΣ0 photoproduction off the neutron. A very preliminary cross section is determined and compared to the prediction, the results appear to support the model

scholarly journals The Nature of Light: What Hidden Behind Young's Double-Slit Experiment?

2021 ◽  
Author(s):  
X. Q. Huang
Keyword(s):  
Scattered Light ◽  
Exchange Property ◽  
Field Energy ◽  
Light Effect ◽  
Light Phase ◽  
Conventional View ◽  
Experimental Diffraction Pattern ◽  
Wave Particle Duality ◽  
Double Slit Experiment ◽  
Double Slit

We experimentally prove that the famous single- and double-slit experimentsare the scattered-light phase transition by slit edges rather thanthe conventional view of the transmitted-light effect by slits. Thenature of the wave-particle duality of light quanta can be well understoodwith the help of the dynamic hypothesis of the quantized chiral photons havingan intrinsic dual-energy (implicit electric field energy and hiddenmagnetic field energy) cyclic exchange property. With the suggestedtheoretical framework, the experimental diffraction pattern of thesingle slit is analytically determined and numerically confirmed.

scholarly journals Event-Response Ellipses: A Method to Quantify and Compare the Role of Dynamic Storage at the Catchment Scale in Snowmelt-Dominated Systems

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1824 ◽  
Author(s):  
Jessica Driscoll ◽  
Thomas Meixner ◽  
Noah Molotch ◽  
Ty Ferre ◽  
Mark Williams ◽  
...  
Keyword(s):  
Water Balance ◽  
Quantitative Relation ◽  
Catchment Scale ◽  
System A ◽  
Time Period ◽  
Ellipse Method ◽  
Streamflow Response ◽  
Dynamic Storage ◽  
Event Response

A method for quantifying the role of dynamic storage as a physical buffer between snowmelt and streamflow at the catchment scale is introduced in this paper. The method describes a quantitative relation between hydrologic events (e.g., snowmelt) and responses (e.g., streamflow) by generating event-response ellipses that can be used to (a) characterize and compare catchment-scale dynamic storage processes, and (b) assess the closure of the water balance. Event-response ellipses allow for the role of dynamic, short-term storage to be quantified and compared between seasons and between catchments. This method is presented as an idealization of the system: a time series of a snowmelt event as a portion of a sinusoidal wave function. The event function is then related to a response function, which is the original event function modified mathematically through phase and magnitude shifts to represent the streamflow response. The direct relation of these two functions creates an event-response ellipse with measurable characteristics (e.g., eccentricity, angle). The ellipse characteristics integrate the timing and magnitude difference between the hydrologic event and response to quantify physical buffering through dynamic storage. Next, method is applied to eleven snowmelt seasons in two well-instrumented headwater snowmelt-dominated catchments with known differences in storage capacities. Results show the time-period average daily values produce different event-response ellipse characteristics for the two catchments. Event-response ellipses were also generated for individual snowmelt seasons; however, these annual applications of the method show more scatter relative to the time period averaged values. The event-response ellipse method provides a method to compare and evaluate the connectivity between snowmelt and streamflow as well as assumptions of water balance.

scholarly journals Role of Na+/H+ exchanger regulatory factor 1 in forward trafficking of the type IIa Na+-Pi cotransporter

2015 ◽  
Vol 309 (2) ◽  
pp. F109-F119 ◽  
Author(s):  
Corey J. Ketchem ◽  
Syed J. Khundmiri ◽  
Adam E. Gaweda ◽  
Rebecca Murray ◽  
Barbara J. Clark ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Critical Role ◽  
Mean Square Displacement ◽  
Active Movement ◽  
Binding Motif ◽  
Late Time ◽  
Cell Fractionation ◽  
Regulatory Factor ◽  
Ok Cells

Na+/H+ exchanger regulatory factor (NHERF1) plays a critical role in the renal transport of phosphate by binding to Na+-Pi cotransporter (NpT2a) in the proximal tubule. While the association between NpT2a and NHERF1 in the apical membrane is known, the role of NHERF1 to regulate the trafficking of NpT2a has not been studied. To address this question, we performed cell fractionation by sucrose gradient centrifugation in opossum kidney (OK) cells placed in low-Pi medium to stimulate forward trafficking of NpT2a. Immunoblot analysis demonstrated expression of NpT2a and NHERF1 in the endoplasmic reticulum (ER)/Golgi. Coimmunoprecipitation demonstrated a NpT2a-NHERF1 interaction in the ER/Golgi. Low-Pi medium for 4 and 8 h triggered a decrease in NHERF1 in the plasma membrane with a corresponding increase in the ER/Golgi. Time-lapse total internal reflection fluorescence imaging of OK cells placed in low-Pi medium, paired with particle tracking and mean square displacement analysis, indicated active directed movement of NHERF1 at early and late time points, whereas NpT2a showed active movement only at later times. Silence of NHERF1 in OK cells expressing green fluorescent protein (GFP)-NpT2a resulted in an intracellular accumulation of GFP-NpT2a. Transfection with GFP-labeled COOH-terminal (TRL) PDZ-binding motif deleted or wild-type NpT2a in OK cells followed by cell fractionation and immunoprecipitation confirmed that the interaction between NpT2a and NHERF1 was dependent on the TRL motif of NpT2a. We conclude that appropriate trafficking of NpT2a to the plasma membrane is dependent on the initial association between NpT2a and NHERF1 through the COOH-terminal TRL motif of NpT2a in the ER/Golgi and requires redistribution of NHERF1 to the ER/Golgi.

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