atomic-physics

I am reading about this apparatus at Wikipedia: https://en.wikipedia.org/wiki/Magneto-optical_trap And there is the following sentence which I don't understand: "As atoms travel away from the field zero at the center of the trap (halfway between the coils), the spatially-varying Zeeman shift brings an atomic transition into resonance which gives rise to a scattering force that pushes the atoms ba…

In two weeks, I am giving two lectures about degenerate Fermi gases in a third-year undergraduate course on statistical mechanics. The textbook is the beautiful book by Schroeder. I want to highlight a few things that are amazing about the Fermi energy. 1. It is given by an incredibly simple expression. E F = ℏ 2 2 m (3π 2 n ) 2/3 2. Besides fundamental constants, it is only determined by the num…

https://doi.org/10.1119/5.0332743 A hidden upper triangular structure was noticed in the paper above. With this insight, the eigenvalues of the harmonic oscillator can be obtained immediately without calculation. The upper triangular structure also exists for the hydrogen atom. We... Read more

This is from APhO 2010, Problem 3, Part (A) When an electron is planted inside liquid helium, it can repel atoms of liquid helium and form what is called an electron bubble. The bubble contains nothing but the electron itself. We shall be interested mainly in its size and stability. We use $\Delta f$ to denote the uncertainty of a quantity $f$ . The components of an electron’s position vector $\v…

Until now, controlling complex quantum systems has largely relied upon understanding how three atomic particles interact. New work demonstrates nonthermal behaviour within chains of Rydberg atoms governed by constraints acting on *four* interacting bodies simultaneously. This combination of ‘blockade’ and ‘antiblockade’ offers an experimentally accessible route towards exploring previously elusiv…

I have come to this as the Time Dependent Equations for the Density Matrix for a Two Level System. $$\frac{d}{dt}\Big(\begin{matrix}ρ_{11}&ρ_{12}\\ρ_{21}&ρ_{22} \end{matrix}\Big)=\Bigg(\begin{matrix}\frac{i}{\hbar}(V_{21}ρ_{12}-V_{12}ρ_{21})+\frac{1}{T_1}ρ_{22}&-\frac{i}{\hbar}V_{12}(ρ_{22}-ρ_{11})+(iω_{21}-\frac{1}{T_2})ρ_{12}\\\frac{i}{\hbar}V_{21}(ρ_{22}-ρ_{11})-(iω_{21}+\frac{1}{T_2})ρ_{12}&\…

Quantum 10, 2197 (2026). https://doi.org/10.22331/q-2026-08-27-2197 Atomic scale qubits, as may be realized in nitrogen vacancy (NV) centers in diamond, offer the opportunity to study magnetic field noise with nanometer scale spatial resolution. Using these spin qubits, one can learn a great deal about the magnetic-field noise correlations, and correspondingly the collective-mode spectra, in quan…

Efficiently controlling heat generation has become a major challenge as the semiconductors used in smartphones, computers and similar devices have become higher-performing and more miniaturized. The way heat is transmitted is determined by the vibration of the atoms that constitute a material, but it is not easy to directly examine, at the atomic scale, how […]

Nature, Published online: 26 August 2026; doi:10.1038/s41586-026-10915-8 Non-destructive single-molecule absorption spectroscopy is achieved by detecting photon recoil from a trapped molecular ion, enabling single-photon-sensitive measurements of molecular vibrational transitions.