Bhaumik Luncheon Young Scientists Seminar (BLYSS)

Friday, March 2, 2018 - 11:45am to 1:00pm
Bhaumik Luncheon Seminar

Adam West, UCLA

Rotation Sensing with a Single Trapped Ion

The burgeoning field of matter-wave interferometry has found numerous applications in precision metrology [1] and searches for new physics [2]. However, very few of these experiments utilize ions, primarily due to their great sensitivity to electric fields. We present an experiment to perform matter-wave interferometry with a single barium ion and realize a Sagnac interferometer for precision rotation sensing [3]. State-of-the-art Sagnac interferometers typically enhance sensitivity by exploiting the scaling with either the enclosed area (fiber-ring gyroscopes [4]) or the particle’s large angular momentum (atom interferometers [5]) – our experiment hopes to combine both of these enhancements. Our method relies on a new scheme for producing state-dependent momentum kicks which may also be broadly applicable to matter-wave interferometry by affording large momentum transfer.

[1] Nature 510, 518-521 (2014) 

[2] Science 349, 849 (2015)

[3] J. Phys. B 50, 6 (2017)

[4] Opt. Lett. 39, 8 (2014)

[5] Phys. Rev. Lett. 107, 133001 (2011)

Bao Minh Hoang, UCLA

Black Hole Mergers in Galactic Nuclei

Almost every galaxy, our own Milky Way included, has a supermassive black hole in its heart. Around these supermassive black holes are the densest stellar structures in the Universe, called nuclear star clusters. These nuclear star clusters are expected to be abundant in stellar-mass black holes (BHs) and BH-BH binaries. Gravitational perturbations from the central supermassive black hole can have significant effects on the BH-BH binary (via the so-called eccentric Kozai-Lidov mechanism). In particular, the eccentricity may approach unity, and the pericenter distance may become sufficiently small that gravitational-wave emission drives the BH-BH binary to merge. We construct a proof-of-concept model for this process and, specifically, we study the eccentric Kozai-Lidov mechanism in unequal-mass, soft BH-BH binaries. We find that this mechanism leads to enhanced merger rate and could potentially compete with other dynamical formation processes for merging BH--BH binaries, such as interactions of stellar BHs in globular clusters, or in nuclear star clusters without a central supermassive black hole.

PAB 4-330