10 research outputs found
A high finesse bow-tie cavity for strong atom-photon coupling in Rydberg arrays
We report a high-finesse bow-tie cavity designed for atomic physics
experiments with Rydberg atom arrays. The cavity has a finesse of and
a waist of m at the cesium D2 line ( nm). With these
parameters, the cavity induces strong coupling between a single atom and a
single photon, corresponding to a cooperativity per traveling mode of at
the cavity waist. To trap and image atoms, the cavity setup utilizes two
in-vacuum aspheric lenses with numerical aperture (N.A.) and is capable
of housing N.A. microscope objectives. In addition, the large atom-mirror
distance ( cm) provides good optical access and minimizes stray
electric fields at the position of the atoms. This cavity setup can operate in
tandem with the Rydberg array platform, creating a fully connected system for
quantum simulation and computation
Atomic physics on a 50 nm scale: Realization of a bilayer system of dipolar atoms
Atomic physics has greatly advanced quantum science, mainly due to the
ability to control the position and internal quantum state of atoms with high
precision, often at the quantum limit. The dominant tool for this is laser
light, which can structure and localize atoms in space (e.g., in optical
tweezers, optical lattices, 1D tubes or 2D planes). Due to the diffraction
limit of light, the natural length scale for most experiments with atoms is on
the order of 500 nm or larger. Here we implement a new super-resolution
technique which localizes and arranges atoms on a sub-50 nm scale, without any
fundamental limit in resolution. We demonstrate this technique by creating a
bilayer of dysprosium atoms, mapping out the atomic density distribution with
sub-10 nm resolution, and observing dipolar interactions between two physically
separated layers via interlayer sympathetic cooling and coupled collective
excitations. At 50 nm, dipolar interactions are 1,000 times stronger than at
500 nm. For two atoms in optical tweezers, this should enable purely magnetic
dipolar gates with kHz speed
Characterizing the local vectorial electric field near an atom chip using Rydberg state spectroscopy
We use the sensitive response to electric fields of Rydberg atoms to
characterize all three vector components of the local electric field close to
an atom-chip surface. We measured Stark-Zeeman maps of and Rydberg
states using an elongated cloud of ultracold Rubidium atoms ( K)
trapped magnetically m from the chip surface. The spectroscopy of
states yields a calibration for the generated local electric field at the
position of the atoms. The values for different components of the field are
extracted from the more complex response of states to the combined electric
and magnetic fields. From the analysis we find residual fields in the two
uncompensated directions of V/cm and V/cm
respectively. This method also allows us to extract a value for the relevant
field gradient along the long axis of the cloud. The manipulation of electric
fields and the magnetic trapping are both done using on-chip wires, making this
setup a promising candidate to observe Rydberg-mediated interactions on a chip.Comment: 8 pages, 5 figure
Can the dipolar interaction suppress dipolar relaxation?
Magnetic atoms in a thin layer have repulsive interactions when their
magnetic moments are aligned perpendicular to the layer. We show experimentally
and theoretically how this can suppress dipolar relaxation, the dominant loss
process in spin mixtures of highly magnetic atoms. Using dysprosium, we observe
an order of magnitude extension of the lifetime, and another factor of ten is
within reach based on the models which we have validated with our experimental
study. The loss suppression opens up many new possibilities for quantum
simulations with spin mixtures of highly magnetic atoms.Comment: 38 pages, 9 figure
Tunable Single-Ion Anisotropy in Spin-1 Models Realized with Ultracold Atoms
Mott insulator plateaus in optical lattices are a versatile platform to study spin physics. Using sites occupied by two bosons with an internal degree of freedom, we realize a uniaxial single-ion anisotropy term proportional to (S^{z})^{2} that plays an important role in stabilizing magnetism for low-dimensional magnetic materials. Here we explore nonequilibrium spin dynamics and observe a resonant effect in the spin alignment as a function of lattice depth when exchange coupling and on-site anisotropy are similar. Our results are supported by many-body numerical simulations and are captured by the analytical solution of a two-site model
Suppressing dipolar relaxation in thin layers of dysprosium atoms
Abstract The dipolar interaction can be attractive or repulsive, depending on the position and orientation of the dipoles. Constraining atoms to a plane with their magnetic moment aligned perpendicularly leads to a largely side-by-side repulsion and generates a dipolar barrier which prevents atoms from approaching each other. We show experimentally and theoretically how this can suppress dipolar relaxation, the dominant loss process in spin mixtures of highly magnetic atoms. Using dysprosium, we observe an order of magnitude reduction in the relaxation rate constant, and another factor of ten is within reach based on the models which we have validated with our experimental study. The loss suppression opens up many new possibilities for quantum simulations with spin mixtures of highly magnetic atoms
Preparation of the Spin-Mott State: A Spinful Mott Insulator of Repulsively Bound Pairs
We observe and study a special ground state of bosons with two spin states in an optical lattice: the spin-Mott insulator, a state that consists of repulsively bound pairs that is insulating for both spin and charge transport. Because of the pairing gap created by the interaction anisotropy, it can be prepared with low entropy and can serve as a starting point for adiabatic state preparation. We find that the stability of the spin-Mott state depends on the pairing energy, and observe two qualitatively different decay regimes, one of which exhibits protection by the gap