Transmission Spectra of Rb 87 atoms near an Optical Nanofiber.

We present measurements of the transmission spectra of 87Rb atoms at 780 nm in the vicinity of a nanofiber. A uniform distribution of fixed atoms around a nanofiber should produce a spectrum that is broadened towards the red due to shifts from the van der Waals potential. If the atoms are free, this also produces an attractive force that accelerates them until they collide with the fiber which depletes the steady-state density of near-surface atoms. It is for this reason that measurements of the van der Waals interaction are sparse. We confirm this by measuring the spectrum cold atoms from a magneto-optical trap around the fiber, revealing a symmetric line shape with nearly the natural linewidth of the transition. When we use an auxiliary 750 nm laser we are able to controllably desorb a steady flux of atoms from the fiber that reside near the surface (less than 50 nm) long enough to feel the van der Walls interaction and produce an asymmetric spectrum. We quantify the spectral asymmetry as a function of 750 nm laser power and find a maximum. Our model, which that takes into account the change in the density distribution, qualitatively explains the observations. In the future this can be used as a tool to more comprehensively study atom-surface interactions.

Bodies on the Line: Violence, Disposable Subjects, and the US-Mexico Border Industrial Complex

Bodies On the Line: Violence, Disposable Subjects, and the Border Industrial Complex explores the construction of identity and notions of belonging within an increasingly privatized and militarized Border Industrial Complex. Specifically, the project interrogates how discourses of Mexican migrants as racialized, gendered, and hypersexualized “deviants” normalize violence against border crossers. Starting at Juárez/El Paso border, I follow the expanding border, interrogating the ways that Mexican migrants, regardless of sexual orientation, have been constructed and disciplined according to racialized notions of “sexual deviance." I engage a queer of color critique to argue that sexual deviance becomes a justification for targeting and containing migrant subjects. By focusing on the economic and racially motivated violence that the Border Industrial Complex does to Mexican migrant communities, I expand the critiques that feminists of color have long leveraged against systemic violence done to communities of color through the prison industrial system. Importantly, this project contributes to transnational feminist scholarship by contextualizing border violence within the global circuits of labor, capital, and ideology that shape perceptions of border insecurity. The project contributes an interdisciplinary perspective that uses a multi-method approach to understand how border violence is exercised against Mexicans at the Mexico-US border. I use archival methods to ask how historical records housed at the National Border Patrol Museum and Memorial Library serve as political instruments that reinforce the contemporary use of violence against Mexican migrants. I also use semi-structured interviews with nine frequent border crossers to consider the various ways crossers defined and aligned themselves at the border. Finally, I analyze the master narratives that come to surround specific cases of border violence. To that end, I consider the mainstream media’s coverage, legal proceedings, and policy to better understand the racialized, gendered, and sexualized logics of the violence.