Supervisors: Prof. Ed Hinds

Coupling dye molecules on a waveguide chip

Single photons are optimal candidates to carry quantum information given their very high coherence time and their ability to carry information in various degrees of freedom. A current challenge is the generation of single photons in a photonic chip,

Dibenzoterrylene (DBT) molecules in a thin film of anthracene (AC) are optimal candidates as a source of single photons given their high at room temperature. Moreover at cryogenic temperature these molecules behave as 2-level atoms resonating at 785nm with a lifetime-limited linewidth of 30 MHz.  

The goal of the project is to investigate photon emission of DBT molecules when embedded in an Anthracene (AC) crystal matrix of sub-wavelength thickness. So far I developed a new method of sub-wavelength thin film growing. This method is based on spin coating DBT in a diethyl ether solution on an plasma-cleaned flat substrate and let the AC evaporate on top. In this way, 2D nucleation can be achieved. The crystals are typically several microns across and have remarkably uniform thickness, which we control between 20 and 150 nm by adjusting the growth time. Stable emission of single photons from DBT molecules can be achieved when growth is carried out in an oxygen-depleted atmosphere. We analyse the polariz

ation of this light to determine the alignment of the molecules with respect to the crystal axis. We aim to control the alignment of the molecules in order to maximise the coupling efficiency between the dipoles and the waveguide.

Coupling DBT molecules on a waveguide chip would be the first step towards the realization of an optical quantum computer.

For more information have a look at the group page:

ttp://www3.imperial.ac.uk/ccm/research/nanophotonics/methods

Talks:

- "Sub-wavelength thin film growth for single photon emission from dye molecules", Experimental Nanotechnology group seminar, King's College London, 10th June 2014

Posters:

- "Novel method for sub-wavelength thin film growth for single photon emission from dye molecules", Topical research meeting on hybrid quantum systems, 16-18th December 2014

- "Novel method for sub-wavelength thin film growth for single photon emission from dye molecules", Photon14 conference, London, 1-4th September 2014

- "Bits of light on a piece of a sort of a computer", Poster including only the ten hundred most used words in the English language, CDT festival of science, Imperial College London, 13th June 2014

-  “Quantum electrodynamics of single dye molecules in dielectric media”, Quantum, Atomic, Molecular and Plasma Physics Conference (QuAMP), Swansea University 8-12th September 2013

  “Quantum electrodynamics of single dye molecules in dielectric media”, 2nd Annual Summer School on Quantum Information, Computing and Control (QuICC), London, 26-29th August 2013

Teaching:

I am involved in teaching both to undergraduates and postgraduates.

For the 2014-15, as for the 2013-14, academic year I will be:

-  Demonstrating 2^nd year laboratory, the “Solid state experiment”

-  Demonstrating the “Electronics and optics” laboratory to the MRes students in the CQD CDT

Outreach:

I try to get involved in outreach across the department.

I collaborated with some students from the Royal College of Art to produce an art exhibition with the title "Physics happens in a dark place". It was based on the world of quantum mechanics and displayed in Shoreditch Town Hall in May 2014. 

I was a presenter at the “Amazing Quantum World show” and January 2013 and then later again on May that year.

I actively participated with other students from the CDT in the Royal Society Summer Exhibition during July 2013 with “banana piano” made thanks to a Makey Makey.