Pauli exclusion principle Definition and 91 Threads

Hello guys, here's something that's been bothering me for a while now: We know the Pauli exclusion principle states that 2 Fermions cannot be in an identical state. So then we have systems like solids or free electron gases, and we calculate and form Fermi-Surfaces, based on the fact that...

The principle states that no two identical fermions in a system can be in the same quantum state, but what I don't fully understand is how you define a "system". For example when you apply statistical thermodynamics to a gas of non-interacting fermions you say that a maximum of one can occupy...

The Pauli Exclusion Principle is the reason more than two electrons cannot occupy the same orbital. This is easy for me to grasp. Why, then, does the Pauli Exclusion Principle make an orbital MORE stable with two electrons as opposed to one? (This is in the interest of knowledge. I'm not...

Hello, I have a question concerning the use of wavepackets to justify the semiclassical approach in solid state physics. In Ashcroft/Mermin, the authors briefly mention that we can construct wave packets and then use them to describe the motion of the center which can be interpreted as what...

This morning I've been thinking about a simple problem whose I can't find out a satisfying solution. We all know that two "close" fermions can't exist in a up-up or down-down spin configuration because of vanishing state function as expressed by the exclusion principle. But what does...

definition of "indistinct" in pauli exclusion principle I'm a little confused about what constitutes a distinct particle. For example, a muon is not an electron as they've got different masses. So the wavefunction for the electron/muon system does not have to be antisymmetric (although it can...

As I understand it, the Pauli exclusion principle states that no two like fermions can be in identical quantum states. I also understand that the quantum states are thus: n, which is the electron shell, l, which is the subshell, m_{l}, which is orbital, and m_{s}, which is spin. However, it...

Suppose there are only two states, and that only two electrons could fit in them (spin states for example), but wouldn't these two states form a basis and so generate an infinite number of states that are linear combinations of these two, so three electrons could be in three different states...

hi, can we say that the Pauli exclusion principle between 2 identical fermions implies logically entanglement because of the antisymmetric wavefunction, that can not be factorized as a tensor product: http://en.wikipedia.org/wiki/Slater_determinant "However, it is not satisfactory for...

does Pauli exclusion principle applied outside the atom?let say 1 electron on Earth and the other on the moon.

I have the following problem understanding Pauli exclusion principle. Two identical fermions can't share the same quantum state. Two bosons can. Now Cooper pairs are bosons made up from fermions. Everything clear up to this point. Now several Cooper pairs can share the same quantum state...

Do bosons tend not to obey Pauli Exclusion Principle? I would appreciate if someone would send me some material about this question, and answer it as well.

A small part of my brain has been bugged by this for a while now, so I figured I'd ask. According to most teachings, as well as the wikipedia entry, there are only 4 fundamental forces. The strong and weak interaction, electromagnetism and gravity, and as far as I know the Pauli exclusion...

"More generally, no two identical fermions (particles with half-integer spin) may occupy the same quantum state simultaneously." Now a quantum state can be setup to describe a collection of atoms, or molecules, or the entire universe in one state. So my question is, two electrons in...

Does the 'Pauli exclusion principle' imply that the universe is only finitely creative? It's rather the philosophy than the physics behind it, I'm interested in. I just wanted to be sure I was interpreting this principle correctly. I thought it meant that there are only a discrete amount of...

Okay, I think everyone here knows what the principle states, so I am not even going over that. Is a proton not a fermion with is +1/2 spin? It has an half integral, hence it must be. However, how is this possible for a proton to be fermion when elements like gold have a lot of protons in the...

Hi, This might be an ignorant question but I have to ask it. The exclusion principle forbids particles from existing with the same quantum numbers, like, if you had 2 electrons, they have quantum numbers n, l, ml and ms, and one out of those 4 has to be different, right? What I was wondering...

According to this website, http://www.particleadventure.org/pauli.html "At one time, physicists thought that no two particles in the same quantum state could exist in the same place at the same time. This is called the Pauli Exclusion Principle, and it explains why there is chemistry." 1-What...

Hello. I was thinking. The collapse of a stellar nucleus into a black hole is an apparent contradiction to the Pauli exclusion principle, right? So which one of those theories fails at that point - quantum mechanics or the theory of relativity? I used to think that it's the theory of...

What happens when a neutron star collapses into a black hole and it's no longer obeying the Pauli exclusion principle? In terms of quantum mechanics? Say it collapses because it gets more massive. A "neutron degeneracy pressure" can be calculated, which is what keeps the neutron star from...

hi, I am studying the Higgs Mechanism these days. And I get two questions. I hope some ones could help me. 1>We know that due to the non-zero VEV, SSB takes place and higgs condensates give masses to bosons and fermions. I wonder that after the SSB and before the universe became as cool...

"older formulation of Pauli exclusion principle" Is there any old formulation of pauli's principle? If so, is it explain that "forbiding the presence of two electrons in the same quantum state"? I need that explanation.

I have a question in my book where five electrons are placed in a infinite square well and I am supposed to calculate the lowest energies. My problem is with the electron configuration. I think that the first two shall be placed in n=1 and then the rest shall be placed in n=2. This since l=0,1...

hi i just wanted to ask if anyone could help me understand this principle i have read around and still seem to be getting nowhere. i found this example but its confusing and does not give explanations http://hyperphysics.phy-astr.gsu.edu/hbase/pauli.html#c1 thanks

Pauli exclusion principle say that no two electrons can occupy the same state. But what would happen if we force them to occupy the same states?

If it takes energy to squeeze matter, then its a force at work right? And what is spin? I can put the quantized nature of spin in the back of my mind for a moment, but what the heck does spin do?

I remember reading about charge independence; about how the energy levels of mirror nuclei (correcting for differences in the colomb term) are identical… I think this suggests that the force between any two nucleons is the same, so the attraction of neutron-proton=proton-proton=neutron-neutron...

So two identical fermions can't occupy the same quantum state. But if one is same except higher in energy then the quantum wave pattern is different so can occupy the same space. Are there any values on the amount of energy needed to make two neutrons exist in the same space? I'm doing a...

Having looked into neutrinos and the process in which they were found I've started looking more in Wolfgang Pauli himself. I've read into this principle but there are a few things I would like to clear up. I have picked out the information I am interested in learning abou. "The Pauli exclusion...

I've just been reading my notes on quantum mechanics and got to the Pauli exclusion principle. The way it was explained makes no sense to me. It says "no two identical fermions can be in the same quantum state". Surely there are some restrictions to the applicability of this statement? It...

We know that two particles can't exist in identical quantum states in the same place, fair enough. However, no particle can be sitting directly on top of another to infinite precision. Therefore, you can always say they're some minimum distance away from one another. Now suppose you have...

hey all, posted this before but no one managed to get it? question off a past paper that it can't do.../ state pauli exclusion principle (can do that) and explain its consequence in an atom (can do that). Use it to determine the values of n, l ml and ms of 10 neon atoms placed in a box at...

sometimes i think, would the pauli exclusion principle still apply if the fermions span a very large spatial distance? for example if i have a very very loooong chain of condensed electrons, wouldn't it be possible that the electrons at both ends occasionaly occupy the same quantum state?

Hi, I am having trouble understanding these concepts. I checked out some websites but it still doesn't help. First of all what's the main postulate? That there exist 2 different kind of particles: bosons and fermions? What are their fundamental definitions which lead to the fact that an integer...

I don't understand how can atoms like heilium-4 which has same amounts of fermions behave like bosons and do not obey pauli's exclusion principle. Do the heilium physically stack up together like laser light, or does it just seem to do that? could someone please explain how superfluids work.

The "Pauli exclusion principle" catastrophe. :!) Recent works with MOTTS have proved the inability of Pauli's work to account for experimental results on the field of high-temp superconductors. Could anyone add his or her own opinion about this? By the way, have any of you guys received...

Does it include all types of particles? All atoms? Thank you.

I know I already posted this question, but it seems to have gotten "lost" among the other questions in the same thread. This is really confusing me now, so I'll ask it again. The pauli exclusion principle says that no two fermions can be in the same quantum state. But if we have three...

The Pauli exclusion principle states that no two fermions can have the same quantum state. My question is, if you could conceivable solve the wave equation for every electron in a large body, perhaps even the entire universe, does this mean that no electrons in that body can have exactly the...

I just finished a unit in statistical mechanics, and i have done some second year quantum mechanics and particle physics at university, however we have only been given the Pauli Exclusion principle and told that fermions obey it, but that bosons do not. My question is, does the Exclusion...

Could the Pauli exclusion principle be due to a force that has a 1 / r dependency where r is the distance between two electrons. Then in the case of electron degeneracy pressure in neutron stars could we say that uncertainty in momentum x uncertainty in position arises from a repulsive...