Questions tagged [exchange-interaction]

A repulsive force that exists in quantum mechanics between identical fermions due to the Pauli exclusion principle.

14 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
6
votes
2answers
211 views

Which mechanism causes ferromagnetism in iron?

There are at least three different mechanisms which can give rise to ferromagnetic order in iron. First is due to the band electrons called band magnetism or itinerant magnetism which is an exchange ...
2
votes
0answers
81 views

spin conservation in exchange polarization process

Exchange polarization is the process by which spin is transferred between an electron beam and a system of polarized atoms (with a single valence spin). The process occurs as a result of the Pauli ...
1
vote
0answers
40 views

Exchange Interaction Time Evolution

This is a hypothetical based on a result in Griffiths (which is my level of QM understanding). In it, he derives an "exchange force" - two particles states A and B, a two-particle state composed of ...
1
vote
0answers
126 views

Attractive exchange energy and correlation energy of different spin in DFT

In DFT, why do most texts ignore/don't mention the attractive exchange "force" between two antiparallel spins electrons? The repulsive "exchange" force of two same spins electrons are always ...
1
vote
0answers
63 views

Is there an exchange of electrons between two Cooper pairs in the BCS state?

The BCS state is $$\left|\psi\right>=\prod_k \left(u_k +v_k c_{k\uparrow}^\dagger c_{-k\downarrow}^\dagger\right)\left|0\right>$$ which pairs all the electrons into Cooper pairs. The ...
1
vote
0answers
26 views

Is Blatt-Weisskopf's treatment of nuclear forces still relevant today?

As in the title, is the treatment of nuclear forces by Blatt and Weisskopf, as in Chapter III of "Theoretical Nuclear Physics", still relevant today, especially with regard to the role of exchange ...
1
vote
1answer
96 views

magnetic and electric interactions in atomic level

From what I understand Van der Waals (VDW) forces are the primary source of inter-molecular interaction. There are three different possible origins for van der Waals forces: permanent dipole-permanent ...
0
votes
0answers
25 views

Hund's Rule Coupling in an Effective Hamiltonian/Lagrangian

I am reading a book on Skyrmions, and I am at the part where the interaction of skyrmions with electrons is discussed. The chapter speaks of Spin-Transfer Torque (STT) and makes the following ...
0
votes
0answers
62 views

Wigner-Seitz radius and Spin-polarized Density Functional Theory (DFT) calculations

The density functional theory (DFT) is widely used to predict the electronic structure of materials. The electron density is the fundamental variable in DFT. However, some DFT codes (eg. VASP) use ...
0
votes
0answers
55 views

How to determine exchange particle of two-to-two process?

For the process, $e^+e^- \rightarrow e^+e^-$ I know that the exchange particle is a photon and for the process $\gamma\gamma \rightarrow e^+e^-$, the exchange particle would be an electron but I'm not ...
0
votes
0answers
22 views

Exchange stiffness for HCP

I am studying the exchange interaction, which can be described with the Heisenberg Hamiltonian: $\hat{H} = -\sum_{i,j}J_{ij}\hat{\mathbf{S_i}}\cdot \hat{\mathbf{S_j}}$ In the framework of constant ...
0
votes
0answers
17 views

3d transition metal atoms magnetization

When trying to characterize the magnetic nature of different atomic elements, 3d transition metals have stood out in a few papers that I have read but I still have a few questions about them. As I ...
0
votes
0answers
107 views

Triplet states and the Hund's rule in identifying the ground state configuration (open shell)

I referred to some of the questions about Hund's rule on StackExchange, such as this for example, but still wasn't able to have my question resolved. (the wikiepdia page has $E_{ex} = C - \frac{1}{2}...
0
votes
0answers
55 views

Heisenberg exchange term in phenomenological nuclear potentials

In phenomenological nucleon-nucleon potentials there are three exchange forces terms: $V_M=V_M(r) P_{x}$ : Majorana exchange (exchange of position coordinates, $P_{x}$ is the operator of exchange of ...