Physics Book - User contributions [en]

Spin

2020-04-19T21:46:47Z

Clairebuchanan:

'''Currently editing: clairebuchanan, Spring 2020'''
== Overview ==

Spin is an intrinsic property that is carried by all elementary particles, composite particles, and atomic nuclei. It is a form of angular momentum, the other form being orbital angular momentum. It has never been observed directly, but is has been inferred from experimental data, namely the Stern-Gerlach Experiment.

Spin is usually thought of as a particle rotating about its own axis. This idea was proposed by Ralph Kronig, George Uhlenbeck, and Samuel Goudsmit and later expanded on by Wolfgang Pauli.

== Properties ==

'''Spin Quantum Number'''

The quantum spin number is a number that describes properties about the quantum spin. It is a positive number that is determined by s = n/2, with n being any non-negative number.

'''Madnitude'''

Since spin is a vector quantity, it has both a magnitude and a direction. All similar elementary particles have the same magnitude of spin angular momentum which is given by the spin quantum number, Ms. The quantum spin number is usually represented as a unitless value. This is due to the fact that is is expressed as a multiple of the Planck Constant. The actual unit of spin is the Joule-second.

'''Direction'''

Due to its quantum nature, it is difficult to measure the direction of spin. Actually, when measuring spin around the x-axis, spin information on the y and z-axes is destroyed. Therefore, it is easier to describe the direction more abstractly.

All possible spin directions are described by the expression "2s+1."

For a spin-1/2 particle, the amount of all possible directions is 2. These directions are -1/2 and 1/2. These states are described as "spin-up" and "spin-down."

For a spin-3/2 particle, the amount of possible directions is 4. These directions are -3/2, -1/2, 1/2, and 3/2.

Spin

2020-04-19T21:46:11Z

Clairebuchanan:

'''Claire Buchanan, Spring 2020'''
== Overview ==

Spin is an intrinsic property that is carried by all elementary particles, composite particles, and atomic nuclei. It is a form of angular momentum, the other form being orbital angular momentum. It has never been observed directly, but is has been inferred from experimental data, namely the Stern-Gerlach Experiment.

Spin is usually thought of as a particle rotating about its own axis. This idea was proposed by Ralph Kronig, George Uhlenbeck, and Samuel Goudsmit and later expanded on by Wolfgang Pauli.

== Properties ==

'''Spin Quantum Number'''

The quantum spin number is a number that describes properties about the quantum spin. It is a positive number that is determined by s = n/2, with n being any non-negative number.

'''Madnitude'''

Since spin is a vector quantity, it has both a magnitude and a direction. All similar elementary particles have the same magnitude of spin angular momentum which is given by the spin quantum number, Ms. The quantum spin number is usually represented as a unitless value. This is due to the fact that is is expressed as a multiple of the Planck Constant. The actual unit of spin is the Joule-second.

'''Direction'''

Due to its quantum nature, it is difficult to measure the direction of spin. Actually, when measuring spin around the x-axis, spin information on the y and z-axes is destroyed. Therefore, it is easier to describe the direction more abstractly.

All possible spin directions are described by the expression "2s+1."

For a spin-1/2 particle, the amount of all possible directions is 2. These directions are -1/2 and 1/2. These states are described as "spin-up" and "spin-down."

For a spin-3/2 particle, the amount of possible directions is 4. These directions are -3/2, -1/2, 1/2, and 3/2.