Electron Spin Sings in a Magnetic Field
A laser beam hits a shiny crystal, and comes back different: slightly shifted in color, with a different polarization. In a magnetic field, this transformation of light becomes especially noticeable.
Quantum Magnet Reveals Hidden Symmetry
A pale green crystal was placed in a magnetic field and cooled below one kelvin — almost to absolute zero. Inside it hide chains of copper atoms that behave like tiny magnetic needles. Usually their orientation is chaotic, but the strong field and cold make the needles align in a unified impulse, like soldiers on a parade ground.