# Atomic Physics Seminar

Optical atomic magnetometers are among the most precise magnetic sensors today, reaching sensitivities up to 0.16 fT/sqrt(Hz). While the AC Stark effect is one of the noise sources in atomic magnetometers, it can be utilized to improve these devices. The effect of the vector part of the AC Stark operator on alkali atoms is equivalent to applying a magnetic field in the direction of the light propagation. We use this effect to create an all-optical vector magnetometer with 0.2 pT/sqrt(Hz) sensitivity to the field magnitude and 4 mrad/sqrt(Hz) sensitivity to the field direction, as well as a scalar magnetometer driven by a fictitious rf field with 40 fT/sqrt(Hz) sensitivity.

*Berkeley*

**Available Downloads:**

TBD

*University of Pennsylvania*

**Available Downloads:**

Atomic Hong-Ou-Mandel effect: a mile-stone in Quantum Atom Optics

*Institut d’Optique*

**Available Downloads:**

*NYU*

**Available Downloads:**

*various*

**Available Downloads:**

*Urbana-Champaign*

**Available Downloads:**

Coulomb interactions limit the brightness of charged particle beams. Controlling the effects of nonlinear beam expansion (space charge) and disordered inter-particle scattering is of critical importance for applications ranging from ultrafast electron diffraction to injectors for particle accelerators. In this talk I will show that ultra-cold ion bunches extracted from laser-cooled atoms can be used to observe the effects of Coulomb interactions with unprecedented detail. Arbitrarily shaped bunches are created to reverse the space-charge problem, and excitation of the cold atoms to Rydberg states prior to ionisation reduces the disorder-induced heating effect. I will present our experimental results that demonstrate improved beam brightness and models and simulations of the effects.

*University Melbourne*

**Available Downloads:**

Conventional methods of quantum simulation rely on kinectic energy determined by free particle dispersions or simple sinusoidal optical lattices. Solid state sytems, by contrast, exhibit a plethora of band structures which differ quantitatively, qualitatively, and even topologically. To what extent does this variety explain the many electronic phenomena observed in these materials? Here we address this question by subjecting an otherwise simple Bose superfluid to a customized band structure engineered by dynamically phase modulating (shaking) an optical lattice. The engineered dispersion contains two minima which we associate to a pseudospin degree of freedom. Surprisingly, in such a system the Bose superfluid exhibits many new behaviors. The psuedospin develops a ferromagnetic order, which can lead to polarization of the entire sample or to sub-division into polarized domains. The excitations of the system also exhibit the roton-maxon structure associated with strong interactions in superfluid helium.

*University of Chicago, James Franck Institute and Department of Physics*

**Available Downloads:**

ing two classes of ultralong-range Rydberg molecules known as trilobite" and<br>

butter<br>

y" molecules. These molecules are predicted to have giant, body-xed<br>

permanent dipole moments on the order of 1000 Debye. The two classes of<br>

molecules are distinguished by the relative dominance of the s-wave and p-wave<br>

electron scattering. We present spectra for (nS1=2 +6S1=2)3 molecules, where<br>

n = 37, 39 and 40, and measurements of the Stark broadenings of selected<br>

trilobite states in Cs due to the application of a constant external electric eld.<br>

Additionally, we present measurements of spectra and Stark splittings for p-<br>

wave dominated (nS1=2 + 6S1=2)3 molecules, where n = 31 and 32.<br>

*University of Oklahoma*

**Available Downloads:**

<br>

Modular quantum networks may involve the use of different types of qubits to create a large scale network. Heralded entanglement between qubits using photon interference is a powerful tool to create entanglement within heterogeneous quantum systems. We experimentally demonstrate the entanglement of non-identical qubits by interfering distinguishable photons emitted from distinguishable trapped ions without significant loss of remote entanglement rate or fidelity.

*University of Maryland*

**Available Downloads:**