Questions tagged [quantum-spin]
Fundamental characteristic property of particles which together with orbital angular momentum acts as the generator of rotations and which doesn't have a classical equivalent but is sometimes compared to and contrasted with classical intrinsic angular momentum.
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Does spectroscopy count as a measurement of electron spin?
There was some debate in my modern physics course about the statement
"The spin of an electron can only be measured in the presence of an external magnetic field".
So far in the course, ...
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How the energy-momentum tensor comes from the action in Kalb-Ramond (KR) gravity? [closed]
The action
\begin{align}\label{action}
S=\int d^4x\sqrt{-g}\bigg[\frac{1}{2\kappa}\bigg(R-\varepsilon\, B^{\mu\lambda}B^\nu\, _\lambda R_{\mu\nu}\bigg)-\frac{1}{12}H_{\lambda\mu\nu}H^{\lambda\mu\nu}-V(...
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How does an Particle changes spin like other particle randomly, how do they give information to each other? [closed]
Im an 7th grader so I request everyone who are answering this question please give answer in simple words.
A electron is spin up and the other electron is spin down then suddenly how does the electron ...
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How does a magnetic field generate and spread?
I recently studied electron spin and magnetic fields. But I'm unable to understand how the magnetic field arises from this spin
All answer I have gotten are that this is a property of electrons
But I ...
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Bargmann–Michel–Telegdi (BMT) equation derivation?
What is the relativistic equation capturing the equation of motion of an electron going through the Stern-Gerlach experiment in classical mechanics? After some googling it seems I'm after a derivation ...
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Eigenvalues of integrable Floquet system
Consider Kicked field Ising model Hamiltonian given as follows. (I am following the this paper, relevant calculations are in appendix A.)
$$
H_I=2 J \sum_k\left[\cos k\left(\hat{b}_k^{\dagger} \hat{b}...
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Quantum Computing Bloch Sphere Convention [closed]
Could somebody please explain why the convention for the Bloch sphere of a qubit has the $|0>$ state pointing up and the $|1>$ pointing down? I understand that the Bloch sphere representation ...
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What would Spin Operator and Spin State Vectors be in higher dimensions?
If we represent spin quantum state of a particle in $\pm z$ direction with $\vert\pm\rangle$ then we know that the state vectors in remaining $x$,$y$ directions would be such that:
$$\vert\langle S_x;...
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Do the canonical twisting bundles play a role in quantum physics?
$\Bbb {CP}^1$ the Riemann sphere appears in quantum physics as the Bloch sphere, and is the natural home for two-dimensional phenomena such as spin. It is sometimes said that bundle theory is relevant ...
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What is Talagrand's "massive Weyl spinor"?
In the book What is a Quantum Field Theory by Michel Talagrand, he introduces (in §10.15) a "massive Weyl spinor."* In physics, common wisdom says there is no such thing. A quick internet ...
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Spin projection of Dirac field
I am very much confused about the spin projection operator of the Dirac field. I am not getting proper resources regarding this. From what I understood, in analogy with the non-relativistic case, we ...
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Belinfante-Rosenfeld Stress-Energy Tensor of a Dirac Lagrangian [duplicate]
I have currently been searching for the form of the Belinfante-Rosenfeld Stress-Energy tensor to calculate the stress energy of a Dirac field (because the tensor derived from Noether’s Theorem is not ...
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Can the spin of a free electron be determined from the Stern-Gerlach experiment?
If free charged electrons would pass through the inhomogeneous field, would they experience a deflection that could help determine their spin and exhibit two fringes on the detector sheet? Is the ...
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Is there a meaningful way to define an inertia tensor for a wave function?
In classical mechanics the inertia tensor for a density field $\rho(x,y,z)$ inside volume $V$, is defined as:
$$
\iiint_V \rho(x,y,z)(||{\mathbf r} ||^2 {\mathbf I}_3 - {\mathbf r}\otimes{\mathbf r})...
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Why are fundamental particle spins so small? [duplicate]
So by my understanding, all the particles known to exist are either spin 1, 1/2 or 0. While I don't follow the details, I've also heard the spin-statistics theorem's conclusion that in 3+1D spacetime, ...
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