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1 vote
1 answer
88 views

Do Helium-4 atoms behave like photons?

I know that the Helium-4 atom is a boson. Does this mean that, like photons, many Helium-4 atoms can be placed at the same point in space? How its possible? It includes fermions (Protons, Neutrons, ...
reza's user avatar
  • 209
1 vote
1 answer
80 views

Amplitude superposition for different kinds of particles

We have seen that the probability of finding a particle at a particular point is the square of its wave function. In the double slit experiment, we notice that wave functions add up and the resultant ...
Users's user avatar
  • 426
-1 votes
1 answer
84 views

A simple question in quanum mechanics on position and momenum eigenstates

The eigenfunctions (eigenstates) for the momentum of a particle are given by the plane waves $$\phi(x,t) = \sin(kx - \omega t)$$ If we sum a large number of these waves in a range from $0$ to $k_m$, ...
Anky Physics's user avatar
4 votes
2 answers
120 views

Semi-classical Quantum Ping-Pong in an infinite well potential

The general one particle state in a simple infinite well of size $L$ is a superposition of all the Hamiltonian eigen-states: $$\tag{1} \psi(x, t) = \sqrt{\frac{2}{L}} \sum_{n = 1}^{\infty} c_n \, e^{-\...
Cham's user avatar
  • 7,592
1 vote
0 answers
37 views

Can other objects feeling the gravitational effect of a particle that is in a state of superposition cause its wavefunction to collapse? [duplicate]

When I feel the slight gravitational pull of one particle that is in a state of superposition and I measure the exact pull at any given instant does the wavefunction collapse? If particle A constantly ...
The Burger King's user avatar
0 votes
2 answers
80 views

Can two normal 1D waves form a wave packet?

I have a confusion A wave packet is described by the superposition of two wave functions: $$Ψ_1(x,t)=A\sin(k_1x−ω_1t)$$ and $$Ψ_2(x,t)=A\sin(k_2x−ω_2t),$$ where $k_1=2.0×10^6\text{m}^{−1}$, $k_2=3.0×...
Prasoon Raj's user avatar
0 votes
0 answers
55 views

Circular wave superposition

(Per title, I do mean circular wave, not radial wave.) I'm trying to learn about wave mechanics through some 3D simulations, and I've arrived at an interesting case that I can't seem to answer through ...
Nolnoch's user avatar
1 vote
0 answers
65 views

Why discarding the linear combination of solutions?

In Griffiths's textbook (Introduction to quantum mechanics), part I, 4.1.2, he's solving Schrodinger equation in three dimensions, after separating the variables $Y(\theta, \phi) = \Theta(\theta)\Phi(\...
Arthur's user avatar
  • 11
2 votes
1 answer
96 views

Understanding the potential step for a particle in 1D

In an exercise, I consider a particle moving from $x=-\infty$ towards a potential step, where $V(x)=0$ for $x\leq 0$ and $V(x)=V_0$ for $x>0$. If we consider the case of $0<E<V_0$, we have; $$...
Rasmus Andersen's user avatar
0 votes
3 answers
586 views

How to check that any linear combination of solutions is itself a solution to the time-dependent Schrödinger equation?

David Griffiths states in 'Introduction to Quantum Mechanics': The general solution is a linear combination of separable solutions. As we're about to discover, the time-independent Schroedinger ...
Rasmus Andersen's user avatar
0 votes
1 answer
57 views

Are energy eigenfunctions of a particle in one dimensional box orthogonal to each other?

For a particle in one dimensional box, its State Ψ(t=0) is defined as: $Ψ= \frac{3}{5}Φ_1(x)+\frac{4}{5}Φ_3(x)$ I want to find out $|Ψ(0)|^2$. My question is that as energy eigenfunctions $Φ_1(x)$ and ...
Dinesh Katoch's user avatar
0 votes
1 answer
120 views

Why is a combination of stationary states not stationary, given the actual probability does seem to be so?

EDIT: So I thought about it and I found a trivial mistake, the eigenstates are only orthogonal over either all space or some specific interval (for example in an infinite square well), meaning that ...
agaminon's user avatar
  • 1,775
7 votes
2 answers
1k views

Why does superposing an infinite number of waves of different wavenumbers eliminate periodicity and may sometimes result in a localised wave?

I am studying how wave packets are defined in quantum mechanics, but I am finding it hard to intuitively understand why superposing an infinite number of waves of different wavenumbers $k$ may ...
cookiecainsy's user avatar
1 vote
2 answers
76 views

How much does the collapse of the wave function reveal about the state of the quantum prior to collapse?

The best way I can pose this question is through an example: suppose a photon passes through a beamsplitter, putting the photon into a superposition of the two paths (reflected or passed through), and ...
OneStrangeQuark's user avatar
0 votes
3 answers
126 views

In slit experiment: is it one wave function before and two wave functions after the split?

Forgive my round-about background to the question: I'm curious how the experiment "fires electrons slowly that interact with themselves"... I'm thinking that's just a simplification? I feel ...
Simon's user avatar
  • 129

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