We demonstrate a method of sensitive detection and thermometry of individual modes in cold (sim1 mK), planar one-component ion plasmas. Exploiting precise control over the valence electron spins of several hundred crystallized 9Be+ confined in a Penning trap, we apply a homogeneous, spin-dependent optical dipole force to excite arbitrary transverse modes with an effective wavelength approaching the interparticle spacing (sim20 mum). Coherent mode excitations as small as 2 nm are detected via entanglement of spin and motional degrees of freedom. Fits to resolved spectra yield individual mode temperatures, facilitating more detailed characterization of plasma heating. Measured mode frequencies are in excellent agreement with those obtained from theory.
Citation: Physical Review Letters
Pub Type: Journals
non-neutral plasmas, one-component plasmas, quantum entanglement, transverse plasma modes