THE VIBRATIONAL SPECTRA AND STRUCTURE OF SODIUM BROMOACETATE AND SODIUM BROMOACETATE−d2-d_{2}

This work was supported in part by the U. S. Air Force under contracts F33615-70-C-1021 and F33615-72-C-1040 and by the Miami University Research Committee. Present address of R.L. Kleinlein: Sherwin-Williams Company, Research Center, 10909 Cottage Grove Avenue, Chicago, Illinois, 60628.Author Institution: Department of Chemistry, Miami UniversityThe complete vibrational spectra of crystalline sodium bromoacetate and sodium bromoacetate$-d_{2}$ have been recorded and a vibrational assignment proposed. The intermolecular coupling of these compounds is quite strong and the data is consistent with a centrosymmetric unit cell containing at least four molecules. The Product Rule calculations support a structure in which the bromine atom is rotated out of the plane of the remaining heavy atoms, but the frequency of the carbon-bromine stretching mode indicates that the amount of rotation is not large

Loading and compression of a single two-dimensional Bose gas in an optical accordion

http://arxiv.org/abs/1611.07681International audienceThe experimental realization of two-dimensional (2D) Bose gases with a tunable interaction strength is an important challenge for the study of ultracold quantum matter. Here we report on the realization of an optical accordion creating a lattice potential with a spacing that can be dynamically tuned between 11 and 2 μm. We show that we can load ultracold 87Rb atoms into a single node of this optical lattice in the large spacing configuration and then decrease nearly adiabatically the spacing to reach a strong harmonic confinement with frequencies larger than ωz/2π=10 kHz. Atoms are trapped in an additional flat-bottom in-plane potential that is shaped with a high resolution. By combining these tools we create custom-shaped uniform 2D Bose gases with tunable confinement along the transverse direction and hence with a tunable interaction strength

Interacting topological edge channels

Electrical currents in a quantum spin Hall insulator are confined to the boundary of the system. The charge carriers behave as massless relativistic particles whose spin and momentum are coupled to each other. Although the helical character of those states is already established by experiments, there is an open question regarding how those edge states interact with each other when they are brought into close spatial proximity. We employ an inverted HgTe quantum well to guide edge channels from opposite sides of a device into a quasi-one-dimensional constriction. Our transport measurements show that, apart from the expected quantization in integer steps of 2e2/h, we find an additional plateau at e2/h. We combine band structure calculations and repulsive electron\u2013electron interaction effects captured within the Tomonaga\u2013Luttinger liquid model and Rashba spin\u2013orbit coupling to explain our observation in terms of the opening of a spin gap. These results may have direct implications for the study of one-dimensional helical electron quantum optics, and for understanding Majorana and para fermions