arXiv subjects

Weilong She

Publications and source records attributed to Weilong She.

7 recordsLinked to original sources

arXiv2023

What is the meaning of physical quantity $\nu$ in the expression of photon energy $h\nu$?

It is well known that, for an incident light of not so high intensity and in a certain range of frequency, the stopping voltage of photoelectric effect is independent of the intensity but dependent on the frequency of the light, which is described by the equation $V = h\nu /e - {W_0}/e$, where $V$ is the stopping voltage, $h$ is the Planck constant, $\nu$ is the frequency of incident light, $e$ is the electron charge, and $W_0$ is the work function. It means that the larger the frequency of incident light, the higher the stopping voltage is. However, the present experiment finds that for a non-monochromatic incident light, the stopping voltage is not determined by the maximum frequency component of the incident light, but by the maximum center frequency of all the wave train components (with different center frequencies) involved in the incident light, that is to say, in the photon energy expression $h\nu$, physical quantity $\nu$ does not refer to the frequency of a monochromatic light, but represents the center frequency of a wave train spectrum. The spectral bandwidth of a wave train component can be as large as 122 nm in visible and near-infrared region. This should arouse more attention in the study of energy exchange between light and matter.

physics.optics↗

arXiv2021

Shortened effect of coherence length of light due to nonselective linear absorption

Coherence length is an important feature of a real light wave. From the Michelson interference of He-Ne laser beam, it is found that the coherence length of the beam decreases with the decrease of intensity when the laser beam passes through a nonselective absorption filter and the intensity becomes low enough. This is a novel experimental phenomenon in optics, which verifies the characteristic of discrete wavelet structure of light for the first time.

physics.gen-ph↗

arXiv2020

Discrete wavelet structure and discrete energy of a classical plane light wave

In this letter, the wavelet transform is used to decompose the classical linearly polarized plane light wave into a series of discrete Morlet wavelets. It is found that the energy of the light wave can be discrete, associated with its discrete wavelet structure.It is also found that the changeable energy of a basic plane light wave packet or wave train of wave vector $\mathord{\buildrel{\lower3pt\hbox{$\scriptscriptstyle\rightharpoonup$}}\over k} $ and with discrete wavelet structure can be with the form of ${H_{0k}} = n{p_{0k}}ω$ $(n = 1,2,3,...)$, where $n$ is the parameter of discrete wavelet structure, $ω$ is the idler frequency of the light wave packet or wave train, and ${p_{0k}}$ is a constant to be determined.This is consistent with the energy division of $P$ portions in Planck radiation theory, where $P$ is an integer. Finally, the random light wave packets with $n=1$ are used to simulate the Mach-Zehnder interference of single photons, showing the wave-particle duality of light.

physics.optics↗

arXiv2011

A phenomenology condition other than zero resistance and a possible pairing mechanism of holes-electrons for superconductivity

The underlying mechanism of unconventional high-temperature superconductivity is a great challenge to condensed matter physics. However, zero dissipation of electric current is the commonness of superconductors whether they are conventional or unconventional ones. In this presentation, the Ohm law in a nonmagnetic conductor is derived from a set of modified electromagnetic equations that involve Maxwell ones. It is found that, the steady current dissipation in a conductor can be expressed as ${J} \cdot {E} = {c^2}\rho /(u{\epsilon _r}{\mu _r})$, where J, E,$\rho$,c, u,${\epsilon_r}$ and ${\mu_r}$ are the electric current density, electric field strength, free electric charge density, light speed in vacuum, effective mobility of carriers, relative dielectric constant and permeability, respectively. This relation indicates that, in a steady state of $ J \ne 0$, if $\rho = 0$, then ${J} \cdot {E} = 0$ and the conductor comes into a superconducting state. It is also found that the condition $\rho = 0$ is valid for superconductivity of magnetic materials and is a sufficient than necessary one. When $\rho = 0$ the (involving the Hall electric field strength) becomes zero, which solves the pending problem why vanishing of Hall-effect in some superconducting states, besides, suggests a superconductive pairing mechanism of holes and electrons. Two examples of superconducting state under the condition $\rho = 0$ are discussed.

physics.class-ph↗

arXiv2011

Spin-orbit hybrid entanglement of photons and quantum contextuality

We demonstrate electromagnetic quantum states of single photons and of correlated photon pairs exhibiting "hybrid" entanglement between spin and orbital angular momentum. These states are obtained from entangled photon pairs emitted by spontaneous parametric down conversion, by employing a $q$-plate for coupling the spin and orbital degrees of freedom of a photon. Entanglement and contextual quantum behavior (that is also non-local, in the case of photon pairs) is demonstrated by the reported violation of the Clauser-Horne-Shimony-Holt inequality. In addition a classical analog of the hybrid spin-orbit photonic entanglement is reported and discussed.

quant-ph↗

arXiv2010

Single-photon spin-orbit entanglement violating a Bell-like inequality

Single photons emerging from q-plates (or Pancharatnam-Berry phase optical element) exhibit entanglement in the degrees of freedom of spin and orbital angular momentum. We put forward an experimental scheme for probing the spin-orbit correlations of single photons. It is found that the Clauser-Horne-Shimony-Holt (CHSH) parameter S for the single-photon spin-orbit entangled state could be up to 2.828, evidently violating the Bell-like inequality and thus invalidating the noncontextual hidden variable (NCHV) theories.

quant-ph↗

arXiv2008

Observation of a push force on the end face of a nm fiber taper exerted by outgoing light

There are two different proposals for the momentum of light in a transparent dielectric of refractive index n: Minkowski's version nE/c and Abrahm's version E/(nc), where E and c are the energy and vacuum speed of light, respectively. Despite many tests and debates over nearly a century, momentum of light in a transparent dielectric remains controversial. In this Letter, we report a direct observation of the inward push force on the end face of a free nm fiber taper exerted by the outgoing light. Our results clearly support Abraham momentum. Our experiment also indicates an inward surface pressure on a dielectric exerted by the incident light, different from the commonly recognized pressure due to the specular reflection. Such an inward surface pressure by the incident light may be useful for precise design of the laser-induced inertially-confined fusion.

physics.optics↗