Enforcement of the Domestic Abuse Act in Minnesota: A Preliminary Study

The Minnesota Department of Corrections latest figures esti- mate that over 63,000 incidents of domestic battering occur each year in the state of Minnesota.1 Due to the inefficiencies and gaps in the reporting system, in Minnesota and across the United States, the true magnitude of the problem is difficult to document. Researchers have estimated, however, that over 1.7 million people in the United States have at some time faced a spouse with a gun or a knife, and that well over two million have experienced a beating by their spouse.2 Thus, while accurate documentation is difficult due to the severe under-reporting of incidents of domestic violence, the problem is clearly one of enormous dimensions with far-reaching societal effects. The Minnesota Department of Corrections latest figures esti- mate that over 63,000 incidents of domestic battering occur each year in the state of Minnesota.1 Due to the inefficiencies and gaps in the reporting system, in Minnesota and across the United States, the true magnitude of the problem is difficult to document. Researchers have estimated, however, that over 1.7 million people in the United States have at some time faced a spouse with a gun or a knife, and that well over two million have experienced a beating by their spouse.2 Thus, while accurate documentation is difficult due to the severe under-reporting of incidents of domestic violence, the problem is clearly one of enormous dimensions with far-reaching societal effects

Controlling and Detecting Spin Correlations of Ultracold Atoms in Optical lattices

We report on the controlled creation of a valence bond state of delocalized effective-spin singlet and triplet dimers by means of a bichromatic optical superlattice. We demonstrate a coherent coupling between the singlet and triplet states and show how the superlattice can be employed to measure the singlet-fraction employing a spin blockade effect. Our method provides a reliable way to detect and control nearest-neighbor spin correlations in many-body systems of ultracold atoms. Being able to measure these correlations is an important ingredient to study quantum magnetism in optical lattices. We furthermore employ a SWAP operation between atoms being part of different triplets, thus effectively increasing their bond-length. Such SWAP operation provides an important step towards the massively parallel creation of a multi-particle entangled state in the lattice.Comment: 6 pages, 4 figure

Enforcement of the Domestic Abuse Act in Minnesota: A Preliminary Study

The Minnesota Department of Corrections latest figures esti- mate that over 63,000 incidents of domestic battering occur each year in the state of Minnesota.1 Due to the inefficiencies and gaps in the reporting system, in Minnesota and across the United States, the true magnitude of the problem is difficult to document. Researchers have estimated, however, that over 1.7 million people in the United States have at some time faced a spouse with a gun or a knife, and that well over two million have experienced a beating by their spouse.2 Thus, while accurate documentation is difficult due to the severe under-reporting of incidents of domestic violence, the problem is clearly one of enormous dimensions with far-reaching societal effects. The Minnesota Department of Corrections latest figures esti- mate that over 63,000 incidents of domestic battering occur each year in the state of Minnesota.1 Due to the inefficiencies and gaps in the reporting system, in Minnesota and across the United States, the true magnitude of the problem is difficult to document. Researchers have estimated, however, that over 1.7 million people in the United States have at some time faced a spouse with a gun or a knife, and that well over two million have experienced a beating by their spouse.2 Thus, while accurate documentation is difficult due to the severe under-reporting of incidents of domestic violence, the problem is clearly one of enormous dimensions with far-reaching societal effects

Experimental realization of strong effective magnetic fields in an optical lattice

We use Raman-assisted tunneling in an optical superlattice to generate large tunable effective magnetic fields for ultracold atoms. When hopping in the lattice, the accumulated phase shift by an atom is equivalent to the Aharonov-Bohm phase of a charged particle exposed to a staggered magnetic field of large magnitude, on the order of one flux quantum per plaquette. We study the ground state of this system and observe that the frustration induced by the magnetic field can lead to a degenerate ground state for non-interacting particles. We provide a measurement of the local phase acquired from Raman-induced tunneling, demonstrating time-reversal symmetry breaking of the underlying Hamiltonian. Furthermore, the quantum cyclotron orbit of single atoms in the lattice exposed to the magnetic field is directly revealed.Comment: 6 pages, 5 figure

Fermi-Hubbard physics with atoms in an optical lattice

The Fermi-Hubbard model is a key concept in condensed matter physics and provides crucial insights into electronic and magnetic properties of materials. Yet, the intricate nature of Fermi systems poses a barrier to answer important questions concerning d-wave superconductivity and quantum magnetism. Recently, it has become possible to experimentally realize the Fermi-Hubbard model using a fermionic quantum gas loaded into an optical lattice. In this atomic approach to the Fermi-Hubbard model the Hamiltonian is a direct result of the optical lattice potential created by interfering laser fields and short-ranged ultracold collisions. It provides a route to simulate the physics of the Hamiltonian and to address open questions and novel challenges of the underlying many-body system. This review gives an overview of the current efforts in understanding and realizing experiments with fermionic atoms in optical lattices and discusses key experiments in the metallic, band-insulating, superfluid and Mott-insulating regimes.Comment: Posted with permission from the Annual Review of of Condensed Matter Physics Volume 1 \c{opyright} 2010 by Annual Reviews, http://www.annualreviews.or

Electromagnetically Induced Transparency and Light Storage in an Atomic Mott Insulator

We experimentally demonstrate electromagnetically induced transparency and light storage with ultracold 87Rb atoms in a Mott insulating state in a three dimensional optical lattice. We have observed light storage times of about 240 ms, to our knowledge the longest ever achieved in ultracold atomic samples. Using the differential light shift caused by a spatially inhomogeneous far detuned light field we imprint a "phase gradient" across the atomic sample, resulting in controlled angular redirection of the retrieved light pulse.Comment: 4 pages, 4 figure

Controlling Correlated Tunneling and Superexchange Interactions with AC-Driven Optical Lattices

The dynamical control of tunneling processes of single particles plays a major role in science ranging from Shapiro steps in Josephson junctions to the control of chemical reactions via light in molecules. Here we show how such control can be extended to the regime of strongly interacting particles. Through a weak modulation of a biased tunnel contact, we have been able to coherently control single particle and correlated two-particle hopping processes. We have furthermore been able to extend this control to superexchange spin interactions in the presence of a magnetic-field gradient. We show how such photon assisted superexchange processes constitute a novel approach to realize arbitrary XXZ spin models in ultracold quantum gases, where transverse and Ising type spin couplings can be fully controlled in magnitude and sign.Comment: 10 pages, 9 figure