I've got several thoughts, but none of them is complete.
A general explanation is that when a few atoms form a structure with lowest energy, then when the interfacial energy is low, these independent small groups of particles tend to gather together and form periodic structure.
But why are...
only in the non-interacting BEC case, the chemical potential is zero. And here it indicates that particle number in the the ground state can change, or to put it another way, the ground state is a particle bath.
Thanks zz, my definition is wrong. I think what I described is "quantum liquid" rather than fluid
but i still don't know the definition of qfluid
What's the difference between fluid and liquid?
What I am talking is about theories under thermodynamic limit, so no finite size problem or experimental difficulties. I got some new thoughts today, welcome commence.
I agree with Redbelly98 that it's about energy level crossing or avoiding. Crossing corresponds to a transition, avoiding to a...
More specifically, consider a Hamiltonian with a changeable parameter a. When changing a, the ground state of the system will change. In some cases, one phase crossovers to another, like in other cases, there's a phase transition. What factor determines the difference? Actually I am now working...
I love to learn new things. But I hate to be lost in new things. It seems that I spend a lot of time and learn little. And I wonder if this is a common thing or not when doing research.
I am now a third grade undergraduate student. I do fair job in my studies. Now I have been in a theorectical condensed matter group in my university to learn how to do researches. But after a whole year, I still find that when I want to run into a topic, say Berry phase, or higgs mechanism, I...
I see that the electron transition energy is too small to create particles with mass. Then I think of another question. If there're two atoms, one of which has an electron in excited state. Two kinds of processes are possible under the condition of the conservations of momentum and energy: the...
The question occurred to me when I was thinking about black radiation. It is critically depend on the fact that the photon number is variable. Therefore I wonder why energy level transitions of atoms can only emit out the massless photons, but not any other kind of particles, even some with...