on Wednesday August 8th we will have Ravid Shaniv from Weizmann Institute in Israel as a guest.
He will present a SFB-seminar at PTB, RZB 11, at 10:00 h.

Title and abstract of the talk is:

Radio-frequency dynamical decoupling approach for precision spectroscopy

Ion-based precision spectroscopy research has been growing rapidly in recent years, due to the improvement and discovery of spectroscopic methods, new possible uses and the introduction of new ions as frequency probes. However, from Rabi through Ramsey to current spectroscopic methods, the vast majority of techniques rely on the separation of two quantum levels from all others, and measuring the energy difference between them.

In my talk, I will present an approach in which additional quantum levels are used in order to mitigate unwanted systematic shifts and frequency drifts, drawing inspiration from the quantum information notion of dynamical decoupling (DD). Here, rotations within Zeeman manifolds during the ion interrogation are generated by a radio-frequency oscillating magnetic field. These rotations can be engineered to cancel unwanted phase contributions while letting the desired effect dominate the experimental outcome.

I will describe three proposals and experiments utilizing these DD sequences. The first is a measurement of the quadrupole moment of the 4D level in 88Sr+ ion with the best achieved precision [1]. The second is a proposal and experimental verification for a broadly applicable method to test for local Lorentz invariance violation in atomic systems [2]. Finally, I will describe and show (unpublished) experimental results for a DD scheme aimed at cancelling inhomogeneous shifts on a multi-ion chain, such as quadrupole shifts and magnetic field gradients.

[1] Shaniv, R., Akerman, N., & Ozeri, R. (2016). Atomic Quadrupole Moment Measurement Using Dynamic Decoupling. Physical review letters, 116(14), 140801.

[2] Shaniv, R., Ozeri, R., Safronova, M. S., Porsev, S. G., Dzuba, V. A., Flambaum, V. V., & Häffner, H. (2018). New Methods for Testing Lorentz Invariance with Atomic Systems. Physical review letters, 120(10), 103202.