14 research outputs found
QED theory of the nuclear recoil effect on the atomic g factor
The quantum electrodynamic theory of the nuclear recoil effect on the atomic
g factor to all orders in \alpha Z and to first order in m/M is formulated. The
complete \alpha Z-dependence formula for the recoil correction to the
bound-electron g factor in a hydrogenlike atom is derived. This formula is used
to calculate the recoil correction to the bound-electron g factor in the order
(\alpha Z)^2 m/M for an arbitrary state of a hydrogenlike atom.Comment: 17 page
Trapped electron coupled to superconducting devices
We propose to couple a trapped single electron to superconducting structures
located at a variable distance from the electron. The electron is captured in a
cryogenic Penning trap using electric fields and a static magnetic field in the
Tesla range. Measurements on the electron will allow investigating the
properties of the superconductor such as vortex structure, damping and
decoherence. We propose to couple a superconducting microwave resonator to the
electron in order to realize a circuit QED-like experiment, as well as to
couple superconducting Josephson junctions or superconducting quantum
interferometers (SQUIDs) to the electron. The electron may also be coupled to a
vortex which is situated in a double well potential, realized by nearby pinning
centers in the superconductor, acting as a quantum mechanical two level system
that can be controlled by a transport current tilting the double well
potential. When the vortex is trapped in the interferometer arms of a SQUID,
this would allow its detection both by the SQUID and by the electron.Comment: 13 pages, 5 figure
Nanofriction in Cold Ion Traps
Sliding friction between crystal lattices and the physics of cold ion traps
are so far non-overlapping fields. Two sliding lattices may either stick and
show static friction or slip with dynamic friction; cold ions are known to form
static chains, helices, or clusters, depending on trapping conditions. Here we
show, based on simulations, that much could be learnt about friction by
sliding, via e.g. an electric field, the trapped ion chains over a periodic
corrugated potential. Unlike infinite chains where, according to theory, the
classic Aubry transition to free sliding may take place, trapped chains are
always pinned. Nonetheless we find that a properly defined static friction
still vanishes Aubry-like at a symmetric-asymmetric structural transition,
ubiquitous for decreasing corrugation in both straight and zig-zag trapped
chains. Dynamic friction can also be addressed by ringdown oscillations of the
ion trap. Long theorized static and dynamic one dimensional friction phenomena
could thus become exquisitely accessible in future cold ion tribology
Resistive and sympathetic cooling of highly-charged-ion clouds in a Penning trap
We present measurements of resistive and sympathetic cooling of ion clouds
confined in a Penning trap. For resistive cooling of a cloud consisting of one
ion species, we observe a significant deviation from exponential cooling
behavior which is explained by an energy-transfer model. The observed
sympathetic cooling of simultaneously confined ion species shows a quadratic
dependence on the ion charge state and is hence in agreement with expectations
from the physics of dilute non-neutral plasmas.Comment: 10 figure