Quantum

Energy levels of a relativistic fermion in magnetic field.

A quick derivation of ANO vortices in the context of spontaneous symmetry breaking.

A derivation of the coherent states of quantum harmonic oscillator.

A detailed derivation of quantum harmonic oscillator solution.

Derivation of Thomas-Reiche-Kuhn sum rules for position operator.

Computing hydrogen wave function with little information to remember.

Derivation of Thomas-Reiche-Kuhn sum rules for position operator.

We use the variational principle to prove that one-dimensional attractive potential of any shape supports a bound state.

We use the Born approximation to compute the differential cross section for the elastic scattering of a fast electron by a hydrogen atom in the ground state. We will treat the hydrogen atom as a fixed target with a time-independent charge …

Some fun with two dimensional harmonic oscillator with perturbation