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DWC Seminar Series 2017

 The Dodd-Walls Centre is proud to present a series of seminars hosted by our themes on different topics and everyone is welcome to attend.    Next Friday’s Quantum Fluids & Gases (QFG) Seminar is presented by Niels Kjærgaard, Associate Professor of Physics, University of Otago.

Title:      Scattering experiments on atoms with a Feshbach resonance above threshold

When:    Date: Friday 21 April at 12 noon (sharp)

Room:    Boardroom 320e, Dodd-Walls Centre, Science III + remote locations via Zoom

Anyone can join from anywhere with the use of a laptop or computer via Zoom.

Zoom Meeting ID: 325 816 342 (meeting invite details at end of email)

 

ABSTRACT:

Scattering experiments on atoms with a Feshbach resonance above threshold

 Studies of magnetically tunable Feshbach resonances in ultracold atomic gases have predominantly been carried out in the zero collision-energy limit.  In this brief talk I will describe our recent experiments on threshold collisions at well-defined energies in the vicinity of a narrow magnetic Feshbach resonance by means of a laser-based collider.  Using our collider we can track the magnetic field shift in resonance position as the energy is tuned.  For a narrow resonance this becomes a challenge due to inherent broadening mechanisms of the collider.  We find, however, that the narrow Feshbach scattering feature becomes imprinted on the spatial distribution of atoms in a fashion that allows for an accurate determination of resonance position as a function of collision energy through a shift in center-of-mass position of the outgoing clouds.

DWC Seminar Series 2017


 

DWC Seminar Series 2017

 The Dodd-Walls centre is proud to present a series of seminars hosted by our themes on different topics and everyone is welcome to attend.   Wednesday’s seminar is presented by Dr Amita Deb, Postdoctoral Fellow, Department of Physics, University of Otago, DWC Boardroom 320e and will also be available via Zoom. 

Title:        Electrometers based on Rydberg atoms

When:    Date: Wednesday 12 April 1pm (sharp) until 1.55pm

Room:    Boardroom 320e, Dodd-Walls Centre, Science III + remote locations via Zoom

Anyone can join from anywhere with the use of a laptop or computer via Zoom.

Zoom Meeting ID: 478-489-695 

 

ABSTRACT:

Electrometers based on Rydberg atoms

Rydberg atoms have electron(s) in highly excited states, and therefore are extremely responsive to electric fields. The field can be that of a neighbouring Rydberg atom or a deliberately applied external source.  In this talk, I will present a proposal to implement a miniaturized electric field sensor based on thermal Rydberg atoms in a vapour cell. I will start by briefly outlining the basic physics of Rydberg atoms and how its extraordinarily high polarizability has proved to be a promising tool for quantum manipulations, such as single-photon phase modulations, quantum chemistry and precise electrometry. For electrometric purposes, Rydberg atoms have already proved their worth in RF and microwave domains, which I will describe. I will then discuss near-dc electrometry using Rydberg atoms and how we propose to implement it. It should be mentioned that the idea is expected to form the core of a protected intellectual right in future. 

 

 

DWC Seminar Series 2017