Integrated Calendar

I will describe a long-standing project to fold RNA using some topological aspects of matrix field theory in the large-N limit, in particular some recent work with Orland, Vernizzi, and others. The problem involves elements of biology, mathematics, and physics. The talk will be self-contained, aiming at an interdisciplinary audience.

Seeking technological application of quantum information science is a widespread predilection at the present, particularly in sensing and imaging. Yet, most of the efforts have been limited to a single phase estimation problem, which very few practical applications are. I will show how our attempts to harness the technological potentials of quantum sensing and imaging in its full generality is leading us towards a better understanding of quantum mechanics.

Time and frequency are the most accurately measurable quantities in physics. With relative frequency inaccuracies as low as 10-18, optical clocks open up a new field of search for deviations in the predictions of Einstein’s general relativity, tests of modern unifying theories and the development of new sensors for gravity and navigation.
However, in order to exploit their full potential, optical ion clocks need to integrate over many days to weeks. Scaling up the number of ions for optical clock spectroscopy is a natural way to significantly reduce the integration time, but was hindered so far by the poor control of the dynamics of coupled many body systems.

Our research aims to use ion Coulomb crystals, i.e. many-body systems with complex dynamics, for precision spectroscopy. We have developed scalable linear ion traps with reduced axial micromotion to store multiple ions for clock spectroscopy. Linear chains of 115In+ ions are sympathetically cooled by 172Yb+ ions. Using resolved sideband spectroscopy on the narrow 2S1/2 → 2D5/2 transition in 172Yb+, we have characterized our ion trap for optical clock operation with systematic frequency uncertainties below 10-19.
Storing large ion Coulomb crystals with a high level of control enables us to study many-body physics with trapped ions. The realization of topological defects in 2D crystals opens up a new research field of non-equilibrium dynamics and nonlinear physics in ion Coulomb crystals. We will present recent results on the study of tribology and transport in such a system.