In physics, a quantum (plural quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. The fundamental notion that a physical property can be "quantized" is referred to as "the hypothesis of quantization". This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum.
For example, a photon is a single quantum of light (or of any other form of electromagnetic radiation). Similarly, the energy of an electron bound within an atom is quantized and can exist only in certain discrete values. (Atoms and matter in general are stable because electrons can exist only at discrete energy levels within an atom.) Quantization is one of the foundations of the much broader physics of quantum mechanics. Quantization of energy and its influence on how energy and matter interact (quantum electrodynamics) is part of the fundamental framework for understanding and describing nature.
According to professional scientific literature and to our best understanding, are there any suggestions that entanglement might imply some sort of faster than light signaling between the entangled particles?
I know that according to relativity nothing can travel faster than light, but what...
Hey to all,....
It is now generally believed that information is preserved in black-hole evaporation.
This means that the predictions of quantum mechanics are correct whereas Hawking's original argument that relied on general relativity must be corrected.
However, views differ as to how...
I know in RVB theory that neighbouring Copper atoms form singlet pairs via the superexchange "force". Upon doping with holes, these neutral singlet RVB pairs become mobile and charged and are able to superconduct. I know that the resonating valence bonds are in the copper 3d(x^2-y^2) orbital and...
(0:00 / 0:42) photon going light-speed blender simulation
I have no idea how a mathematician would translate this example into an equation. Every time I've worked with soft bodies I seem to run short of mathematicians buddies. Regardless of the mathematics of continuous object deformation, this...
So what am I doing wrong here? I can clearly observe it, I'm nearly sure I can tell which particles are going throw each slit if I used another laser too. My suspicion is that the electrical current of the photon detector that uses germanium or silicon to detect the particles are influencing the...
I have been working on a relatively simple problem. Just take a quantum wave function for which a physical requirement is that an arbitrary displacement of x or an arbitrary shift of t should not alter the character of the wave, and I want to find the state function solution. A possible guess...
Hello, I am currently studying about entanglement on spin-1/2 chains and I was able to find some information about the mathematical point of view of concurrence but I can't understand the physical meaning of it . Can somebody help me, please?
I tried to find states in direct method using ##\frac{E}{E_0}=\:nx^2+ny^2+nz^2## and ##100\:<nx^2+ny^2+nz^2\:<\:136##
But it was too long, found it using phi approximation there are around 300 energy states, and Python find around 271 states using direct method but I need manual or recursive...
Hi!
I want to self study some of quantum mechanics so i need introductory textbook. I've taken courses on linear algebra that covers all "Linear algebra done right" by Sheldon Axler, multivariable calculus, two courses on general physics and the basics of differentials equations.
I really like...
How do we map experimental measurements of quantum fields, such as those seen in accelerators, to the theory's mathematical formalism? When we see images of particle tracks produced in accelerators such as the LHC, I think it's safe to say a measurement (or series of measurements) has been...
Of course, this question consisted of two parts. In the first part, we needed to calculate the first-order correction. It was easy. In all the books on quantum mechanics I saw, only first-order examples have been solved. So I really do not know how to solve it. Please explain the solution method...
In p.385 of Griffiths QM the vector potential ##\textbf{A} = \frac{\Phi}{2\pi r}\hat{\phi}## is chosen for the region outside a long solenoid. However, couldn't we also have chosen a vector potential that is a multiple of this, namely ##\textbf{A} = \alpha \frac{\Phi}{2\pi r} \hat{\phi}## where...
Is advanced quantum computing the key to achieving the world's first true artificial general intelligence? The astronomical amount of computing power required for an AGI is currently not possible with classical computing.
But then I learned a photon can be split into two or even three photons (red-shifted, energy is conserved), and also photon can lose energy and still be a photon (Raman effect, inelastic scattering). Now, I am not sure what it means when it is said photons are quanta of light (smallest unit of...
If the answer is Yes, then I would ask, if the mirror absorbs a portion of the energy of the photon, so the photon should simply stop existing because we cannot have a smaller package of light than a photon.
If the answer is No, then I would ask why a beam of light (which is made of a big...
Suppose a blind man builds a machine that paints three apples with three colors, either red, blue or green. Once the machine has done this, are the three apples in the following superposition:
or is the wavefunction just one of
It feels like because the man is blind, the apples should be in...
Coulomb's law for three dimensional space is an empirical law that describes the forces between two stationary point charges and is defined as:
\vec{F}=\frac{K q_1 q_2 (\vec{r}_1-\vec{r}_2)}{|\vec{r}_1-\vec{r}_2|^3}
From Coulomb's law, the magnitude and direction of an electric field produced by...
Good afternoon!
I am writing with such a problem, I hope to find someone who could help me. I'm almost desperate! So, there is such a thing as the Braess paradox, this is a classic paradox for roads and power grids, and there is also such an article...
Suppose that we have two atoms with one proton one electron each, and these electrons interact with each other. The states for the electrons are the singlet(S=0) and the triplet states(S=1). My question is if i have to keep the nuclear spin of the protons parallel when i write the states, for...
I was reading a paper on Radical-Pair mechanism (2 atoms with 1 valence electron each) and the author used the hyperfine hamiltonian $$H_{B}=-B(s_{D_z}+s_{A_z})+As_{D_x}I_x+As_{D_y}I_y+as_{D_z}I_z$$ and found the following eigenvalues: a/4 (doubly degenerate) , a/4±B , (-a-2B±2√(A^2+B^2)) ...
Hi, first-time poster here
I'm a student at HS-level in DK, who has decided to write my annual large scale assignment on Schrödinger's equation. My teacher has only given us a brief introduction to the equation and has tasked us to solve it numerically with Euler's method for the hydrogen atom...
Consider page 2 of Toth's paper Entanglement detection in the stabilizer formalism (2005) . To detect entanglement close to GHZ states, they construct entanglement witnesses of the form $$\mathcal{W} := c_0 I - \tilde{S}_{k}^{(GHZ_N)} - \tilde{S}_{l}^{(GHZ_N)},$$
where...
Trying to use <+|+>=1=<-|-> and <-|+>=0 to prove each iteration of the equation, so I have 6 different versions to prove. But the part I'm currently stuck on is understanding how to simplify any given version. I've written out [S_x,S_y]=S_xS_y\psi-S_yS_x\psi and expanded it in terms of the...
Travis Norsen in his paper Quantum Solipsism and Non-Locality seems to believe that Everettian QM implies some sort of solipsism. He falls it FAPP (for all present purposes) solipsism. (I must say that as a geologist this goes over my head a bit!)
However I have recently read Sean Carrolls...
I have just finished reading the book 'Three Roads to Quantum Gravity' by Lee Smolin.
My question interestingly is associated with my geology background. Lee Smolin notes Fay Dowker concludes that if Consistent Histories is true then we cannot deduce the existence of dinosaurs 100 million...
Question
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So I've done a calculation which seems to suggest if I combine the system of a measuring apparatus to say an experimenter who "reacts" to the outcome of the the measurement versus one who does not. Then the change in entropy in both these situations is bounded by:
$$ \Delta S_R...
My question is the physics behind the LASER such as stimulated emission can be only explained by quantum mechanics only. We can represent LASER as coherent state in quantum mechanics only. Then how can we say LASER can be thought of a classical light source?
I was reading mehran kardar (books and lectures) it says the concept of irreversibility comes from an assumption (in which we increase the length scale by interaction disctance between two particles).
So My question is the concept of irreversibility is still valid in the case of 1 particle...
We know that photons (light) are massless but they have momentum. Now suppose I am in the space far away from planets/stars that there is no external force exerts on me, if:
1- I turn on a flashlight (torch), would I be pushed in the opposite direction which the flashlight is facing (Newton's...
Here, are the parts of the plot function
p1 = Plot[Normal[g*Exp[-x^2/2] /. solute[[1]] /. en -> 3], {x, -8, 8},
PlotStyle -> {Dashed, Gray}, PlotLegends -> Automatic];
(* Here, g=1 - x^2 - x^4/6 - x^6/30 - x^8/168 - x^10/1080 , energy en =3 and solute is the series solution of g with...
I am a biology undergraduate interested in abiogenesis.
The entropic explanation for the origin of life is that life is allowed to exist because it increases universal entropy.
I am curious about how far we can take this theory down.
How can you explain the emergence of atoms and atomic...
In "Introduction to Quantum Mechanics", Griffiths derives the following formulae for counting the number of configurations for N particles.
Distinguishable particles...
$$ N!\prod_{n=1}^\infty \frac {d^{N_n}_n} {N_n !} $$
Fermions...
$$ \prod_{n=1}^\infty \frac {d_n!} {N_n!(d_n-N_n)!}$$...
I've already found the turning points, in the case of the left turning point, the local minimum of the potential, ##\delta_{min}=1.11977## when evaluating for an arbitrary value of current ##J=0.9I_C##. The left turning point is therefore ##\delta_r=2.48243##.
I know the Bohr-Sommerfeld...
a.) The potential is a delta function, so ##V \left( r \right) = \frac {\hbar^2} {2\mu} \gamma \delta \left(r-a \right)##, therefore ##V \left( r \right) = \frac {\hbar^2} {2\mu} \gamma ## at ##r=a##, and ##V \left( r \right) = 0## otherwise. I've tried a few different approaches:
1.) In...
The book's procedure for the "shooting method"
The point of this program is to compute a wave function and to try and home in on the ground eigenvalue energy, which i should expect pi^2 / 8 = 1.2337....
This is my program (written in python)
import matplotlib.pyplot as plt
import numpy as...
Part a:
Gate
H
X
Y
Z
S
T
R_x
R_y
Theta
pi
pi
pi
pi
pi/2
pi/4
pi/2
pi/2
n_alpha
(1/sqrt(2))*(1,0,1)
(1,0,0)
(0,1,0)
(0,0,1)
(0,0,1)
(0,0,1)
(1,0,0)
(0,1,0)
Using the info from the table and equation 1, I find:
U_H=(i/sqrt(2))*[1,1;1,-1]
U_X=i*[0,1;1,0]
U_Y=i*[0,-i;i,0]
U_Z=i*[1,0;0,-1]...
hi guys
i am a the third year undergrad student and in this 2nd semester in my collage we should start taking quantum mechanics along with
molecular physics , our molecular physics professor choose a book that we are going to take which is " molecular physics by wolfgang Demtroder "
when i...
To plot ##u(r)## we need to find the solutions for each region. Which is in the relevant equations part. Now, I have to do this numerically. Using python 3.7 I made an ##u## which is filled with zeros and a for loop with if/elseif statement, basically telling it to plot values for whenever...
What exactly is a measurement device and how does it carry out a measurement?
For instance, in the double slit experiment, you always hear about particle/wave duality. When it's not being measured it behaves like a wave but when a measuring device is placed by the slits, it behaves like a...
I’ve never worked with a quantum system with more that two states 1, -1, and I’ve just gotten this homework problem. I'm not sure what it means. Does this mean it has five states? Why are there two 0’s and two 1’s?
hello! I've been trying to read through Sakurai's Modern quantum mechanics textbook ( My goal is to finish the first 3 chapters and understand the Dirac formulation of QM specifically) but I find myself stumbling at many places. Are there any video lectures on the internet that follows this text...
In a typical quantum course we learn how to approximate the ground state of a particular Hamiltonian by making an educated guess at an ansatz with a tunable parameter then calculating the expectation energy for the ansatz. The result will depend on the tunable parameter if done correctly. Then...
Given that operator ##S_M##, which consists entirely of ##Y## and ##Z## Pauli operators, is a stabilizer of some graph state ##G## i.e. the eigenvalue equation is given as ##S_MG = G## (eigenvalue ##1##).
In the paper 'Graph States as a Resource for Quantum Metrology' (page 3) it states that...
Why can't there be a Universal Interpretation of Quantum Mechanics? If you unite Copenhagen and Many Worlds than all other interpretations will fall under the umbrella of a Universal Interpretation of Quantum Mechanics.
The main problem with interpretations seems to be the role of the observer...