1/2 spin particle in a norm-constant magnetic field

In summary, the conversation discusses a curious exercise involving a 1/2 spin particle in a magnetic field with constant magnitude and orientation, rotating at an angular speed. The Hamiltonian for this problem is given by H(t)=-\vec{S}\cdot\vec{B}, and the question is how to solve the Schrödinger equation for this scenario. The solution can be found in section 7.7.2 of the book Quantum Computation and Quantum Information (Neilsen and Chuang), where the use of Pauli matrices in the Hamiltonian is explained due to the spin operator for spin-half particles being written in terms of Pauli's matrices. It is suggested to revisit this problem after completing a quantum mechanics
  • #1
christianpoved
15
0
Hello everybody, I have a curious excercise, there is a 1/2 spin particle in a magnetic field ##\vec{B}(t)## with ##||\vec{B}(t)||## constant, orientated in an angle ##\theta## from the ##z## axis rotating with an angular speed ##\Omega##. The hamiltonian will be

$$H(t)=-\vec{S}\cdot\vec{B}$$

How do I solve the Schrödinger equation for this problem?
 
Last edited:
Physics news on Phys.org
  • #2
christianpoved said:
Hello everybody, I have a curious excercise, there is a 1/2 spin particle in a magnetic field [itex]\vec{B}(t)[/itex] with [itex]|\vec{B}(t)|[/itex] constant, orientated in an angle [itex]\theta[/itex]
from the [itex]z[/itex] axis rotating with an angular speed [itex]\Omega[/itex]. The hamiltonian will be

[itex]H(t)=-\vec{S}\cdot\vec{B}[/itex]

How do I solve the Schrödinger equation for this problem?
It is nicely done in Quantum Computation and Quantum Information (Neilsen and Chuang) section 7.7.2.
 
  • #3
Whoa... thanks, but I feel that i don't understand the solution (i haven't taken the QM course yet), why are they using the pauli matrices in the hamiltonian?
 
  • #4
Well because the spin operator for spin-half particles is written in terms of Pauli's matrices. When we take the 'dot product' of magnetic moment (which is spin operator multiplied by some factor) with magnetic field, we get Hamiltonian as some combination of Pauli's matrices.

May I suggest to revisit this problem after you have completed quantum mechanics course? :)
 
  • #5
Hahahahahaha, I will check it again after i take QM but I have to do it for some "Geometry for physicists" course that I'm taking, is sad that the math is clear but not the physics :(
 

Related to 1/2 spin particle in a norm-constant magnetic field

What is a 1/2 spin particle?

A 1/2 spin particle is a type of elementary particle, such as an electron or a proton, that has a spin quantum number of 1/2. This means that it has half-integer spin, which is a fundamental property of particles that describes their intrinsic angular momentum.

What is a norm-constant magnetic field?

A norm-constant magnetic field is a type of magnetic field that has a constant magnitude and direction throughout its entire space. This is in contrast to a non-constant magnetic field, which can vary in strength and direction at different points in space.

How does a 1/2 spin particle behave in a norm-constant magnetic field?

In a norm-constant magnetic field, a 1/2 spin particle will experience a torque due to its magnetic moment interacting with the magnetic field. This will cause the particle to precess around the direction of the magnetic field, similar to how a spinning top precesses around its axis.

What is the significance of studying 1/2 spin particles in a norm-constant magnetic field?

Studying 1/2 spin particles in a norm-constant magnetic field allows scientists to better understand the behavior and properties of these fundamental particles. This knowledge can then be applied to various fields such as quantum mechanics, particle physics, and materials science.

Are there any practical applications of studying 1/2 spin particles in a norm-constant magnetic field?

Yes, there are practical applications of studying 1/2 spin particles in a norm-constant magnetic field. This includes the development of magnetic resonance imaging (MRI) technology, which uses the principles of spin precession to create detailed images of the body's internal structures.

Similar threads

Replies
1
Views
903
  • Quantum Physics
Replies
10
Views
2K
  • Quantum Physics
Replies
1
Views
804
  • Quantum Physics
Replies
5
Views
655
  • Quantum Physics
Replies
10
Views
2K
Replies
2
Views
713
Replies
2
Views
218
  • Quantum Physics
Replies
12
Views
2K
Replies
1
Views
352
Replies
6
Views
2K
Back
Top