FYI, ist ggfs insbesondere für Chris was. -------- Weitergeleitete Nachricht -------- Betreff: Special DQ-mat Colloquium by Baptist Piest at LUH, 08. April 2025, 4 pm Datum: Fri, 4 Apr 2025 11:20:04 +0200 Von: Anke Schmidt <anke.schmidt@DQ-MAT.UNI-HANNOVER.DE> Antwort an: Anke Schmidt <anke.schmidt@DQ-MAT.UNI-HANNOVER.DE> An: MEMBERS-DQMAT@LISTSERV.UNI-HANNOVER.DE Dear DQ-mat members and interested scientists, We are are pleased to announce the next special colloquium which will take place on *_Tuesday, 08. April 2025_*_ __LUH__, Building 3406, Room 317, Callinstr. 36, 30167 Hannover _ *_15:30-17:00_*Colloquium by *Baptist Piest *SYRTE, Observatoire de Paris, France Title: *Implementation of Delta-Kick squeezing in an atom interferometer* Abstract: Atom interferometers are versatile devices to detect accelerations or rotations with high sensitivity and accuracy with important applications in geodesy, navigation and fundamental physics. The phase readout of light-pulse atom interferometers with classical input states is naturally limited by the quantum projection noise leading to the standard quantum limit. In this case, the sensitivity to accelerations is given by 1/(kT²Sqrt(N)) with the scale factor kT² and the atom number N. Increasing the sensitivity of atom interferometers is one of the main challenges in the field. Conducting experiments in long baseline facilities or microgravity can considerably increase the sensitivity. A different approach to further improve the performance of atom interferometers is given by circumventing the standard quantum limit using entangled states. This has successfully been demonstrated in recent experiments by the groups of J. Thomson [1] and C. Klempt [2]. These experiments made use of strong cavity-atom coupling in a high-finesse cavity and spin-collisions in a dipole trap, respectively. In our experiment we strive to implement and analyze the recently proposed technique of Delta-Kick squeezing [3] and demonstrate an entanglement-enhanced gravimeter operating below shot noise. The entanglement is generated by the non-linear interatomic interactions of a focused Bose-Einstein condensate (BEC) of Rb-87 atoms which leads to momentum squeezing. The experiment is operated at LTE and has previously been used to investigate Casimir-Polder forces between Rb-87 atoms and a polished surface [4]. Since then, it is being prepared for the implementation of Delta-Kick squeezing. In this talk, I will discuss the experimental setup, the planned implementation of the entanglement-enhanced interferometer and show our recent progress. [1] G. Greve et al. Nature *610*, 472-477 (2022) [2] C. Cassens et al. Phys. Rev. X *15*, 011029 (2025) [3] R. Corgier et al. Phys. Rev. Lett. *127*, 183401 (2021) [4] Y. Balland et al. Phys. Rev. Lett *133*, 113403 (2024) Access data for the transfer: Zoom Access:**_https://us04web.zoom.us/j/932734874 <https://us04web.zoom.us/j/932734874> _ This talk is part of the "Virtual Seminar on Precision Physics and Fundamental Symmetries" series and of the SFB DQ-mat colloquium series: https://indico.cern.ch/category/12183/__ Best regard, Anke Schmidt -- Leibniz Universität Hannover DQ-Mat-Office, Room 308 Callinstraße 36 30167 Hannover Tel: +49 511 76214887 Fax: +49 511 76217243 Email:anke.schmidt@dq-mat.uni-hannover.de https://www.dq-mat.uni-hannover.de/ https://www.quest-lfs.uni-hannover.de/ https://www.hitec.uni-hannover.de/ https://www.quantumfrontiers.uni-hannover.de/ https://www.qvls.de