-------- Weitergeleitete Nachricht --------
Dear Members of Working Group WG2,
I would like to invite you to the next talk of our online seminar.
Date and time: Thursday, 18th of June 10:00 CEST
Speaker: Torsten Zache, Universität Innsbruck, Austria
Title: Non-local mass superpositions and optical clock
interferometry in atomic ensemble quantum networks
Abstract: Quantum networks are emerging as powerful platforms for
sensing, communication, and fundamental tests of physics. We
propose a programmable quantum sensing network based on entangled
atomic ensembles, where optical clock qubits realize mass
superpositions arising via mass-energy equivalence, as in atom and
atom-clock interferometry. Our approach uniquely combines
scalability to large atom numbers with minimal control
requirements, relying only on collective addressing of internal
atomic states. This enables the creation of both non-local and
local superpositions with spatial separations beyond those
achievable in conventional matter-wave interferometry with single
atoms. Starting from Bell-type seed states distributed via
photonic channels, collective operations within atomic ensembles
coherently build many-body mass superpositions sensitive to
gravitational redshift. The resulting architecture implements a
non-local Ramsey interferometer, where gravitationally induced
phase shifts are imprinted on non local entangled states and are
read out through local measurements at the network nodes. Beyond
extending the spatial reach of mass superpositions, our scheme
establishes a scalable, programmable platform to probe the
interface of quantum mechanics and gravity, and offers a new
experimental pathway to test atom and atom-clock interferometer
proposals, e.g. for probing gravitational dephasing, in a
network-based quantum laboratory.
The talk will be streamed via Zoom
https://uni-bremen.zoom-x.de/j/67290871943?pwd=o98aQfS9g6iItJDvj93QC3ZP3az8Ph.1
I am looking forward to seeing you for the talk and the subsequent
discussion with Torsten Zache.
With kind regards,
Dennis (Rätzel)
University College London
WG2 leader