Is time reversal broken in an atom with nonzero magnetic moment?

In summary, time reversal symmetry is a fundamental principle in physics that states that the laws of physics should behave the same way if time is reversed. A nonzero magnetic moment breaks this symmetry by introducing a preferred direction in the system. It is not always broken in atoms with nonzero magnetic moments, as it depends on the specific properties and interactions of the atom. Some common examples include hydrogen, helium, and iron atoms. The breaking of time reversal symmetry can have various effects on the behavior of the atom, such as affecting its energy levels and interactions with external fields or particles.
  • #1
wdlang
307
0
it is obvious that the hamiltonian of an atom is time reversal invariant

but how can an atom have non-zero magnetic moment?
 
Physics news on Phys.org
  • #2
Time reversal is equivalent to CP. If you imagine the magnetic moment as being produced by tiny little charges running around in a circle, C flips the sign of their charge, while P makes them run around in the opposite sense. So magnetic dipole moment is even under CP, and consequently even under T. It's the electric dipole moment which is odd under CP and T.
 

Related to Is time reversal broken in an atom with nonzero magnetic moment?

1. What is time reversal symmetry?

Time reversal symmetry is a fundamental principle in physics that states that the laws of physics should behave the same way if time is reversed. This means that if we were to observe a physical process in reverse, it would still follow the same laws and look the same.

2. How does a nonzero magnetic moment affect time reversal symmetry?

A nonzero magnetic moment breaks time reversal symmetry because it introduces a preferred direction in the system. This means that if we were to observe the system in reverse, the direction of the magnetic moment would also be reversed, breaking the symmetry.

3. Is time reversal broken in all atoms with nonzero magnetic moment?

Not necessarily. It depends on the specific properties and interactions of the atom. In some cases, the effects of the nonzero magnetic moment may cancel out, preserving time reversal symmetry. In other cases, it may be broken.

4. What are some examples of atoms with nonzero magnetic moments?

Some common examples include hydrogen, helium, and iron atoms. These atoms all have unpaired electrons, which contribute to their nonzero magnetic moments. However, there are many other atoms and molecules with nonzero magnetic moments as well.

5. How does the breaking of time reversal symmetry in an atom affect its behavior?

The breaking of time reversal symmetry can lead to a variety of effects, depending on the specific system and interactions involved. In some cases, it may affect the energy levels and transitions of the atom. It may also influence the way the atom interacts with external fields or other particles.

Similar threads

Replies
22
Views
1K
Replies
80
Views
3K
Replies
19
Views
2K
  • Quantum Physics
Replies
10
Views
2K
  • Quantum Physics
Replies
4
Views
633
Replies
2
Views
1K
Replies
6
Views
1K
Replies
2
Views
642
Replies
6
Views
839
  • Quantum Physics
Replies
12
Views
2K
Back
Top