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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 QMI Seminar is presented by Jelena Rakonjac, MSc (Physics) University of Otago. 

Title:      Measuring hyperfine coherence times of 167Er:YSO around zero magnetic field

When:    Date: Friday 26 May at 12 noon (sharp)

Venues:  320e, Dodd-Walls Centre, Science III, University of Otago + room 301.411, University of Auckland 

                + Anyone can join from anywhere with the use of a laptop or computer

                Zoom Meeting ID: 325 816 342 

 

ABSTRACT:

 

Rare-earth ion-doped crystals have been shown to have long coherence times for nuclear spin states when using hyperfine transitions with zero first order Zeeman shift (ZEFOZ). This minimizes dephasing from nuclear spin flips. However, this technique has only been utilised with transition energies in an external magnetic field.  One particular rare-earth crystal, erbium-167-doped yttrium orthosilicate (167Er:YSO), has a hyperfine structure that allows ZEFOZ transitions to occur even with no external magnetic field. Using a spin Hamiltonian to model the hyperfine transitions of the ground state of 167Er:YSO, we determined which transition would have the longest coherence time.  We then investigated the hyperfine structure of 167Er:YSO using a tunable cavity and Raman heterodyne spectroscopy. Although we were unable to measure coherence times for any of the ZEFOZ transitions found, we have measured coherence times of 13 and 50 µs for two transitions with zero external magnetic field.

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