Condensed Matter Physics Seminar
“On-chip nanophotonics: controlling light at the single photon level”
Date: 17 March 2017, 3pm-4pm
Venue: C36 Physics
Speaker: Dr Luca Sapienza, University of Southampton
Solid-state quantum emitters are required for quantum information protocols relying on the storage, manipulation, and transmission of the information encoded in single photons through optical cavities and waveguides. Semiconductor quantum dots are particularly promising quantum light sources that can allow both the investigation of fundamental physics phenomena on a chip and quantum technology applications [1].
I will discuss the implementation of quantum dot nanostructures to create simultaneously bright and pure, on-demand, single-photon sources in engineered nanophotonic devices in gallium arsenide [2] and hybrid silicon/III-V materials [3]. I will present different photonic geometries for controlling light propagation, brightness and spontaneous emission rate, based on circular grating and ring cavities. Finally, I will focus on the comparison between highly engineered structures and disordered photonic crystal waveguides, showing efficient light confinement and optical sensing on a silicon nitride platform in the visible range of wavelengths [4].
References:
[1] O. Gozzano, G.S. Solomon, Toward optical quantum information processing with quantum dots coupled to microstructures, Journal of the Optical Society of America B 33, C160 (2016)
[2] L. Sapienza, M. Davanco, A. Badolato, K. Srinivasan, Nanoscale optical positioning of single quantum dots for bright and pure single-photon emission,
Nature Communications 6, 7833 (2015).
[3] M. Davanco, J. Liu, L. Sapienza, C.-Z. Zhang, J.V. De Miranda Cardoso, V. Verma, R. Mirin, S. W. Nam, L. Liu, K. Srinivasan, A heterogeneous III-V/silicon integration platform for on-chip quantum photonic circuits with single quantum dot devices, arxiv.org/abs/1611.07654 (2016).
[4] T. Crane, O.J. Trojak, L. Sapienza, Anderson localisation of visible light on a nanophotonic chip, arxiv.org/abs/1605.08614 (2016).
Grainne Wilkinson
Particle Physics Seminar
Electroweak production measurements at the LHCb experiment
Date: 17 March 2017, 13:45 – 14:45
Venue: Physics C36
Speaker: Dr Will Barter, Manchester
Electroweak production measurements at the LHCb experiment
LHCb is able to make important contributions in areas of research beyond LHCb’s original remit in beauty and charm physics. I will present the latest LHCb measurements of forward Electroweak Boson Production in proton-proton collisions. These results provide unique constraints on the parton distribution functions which describe the inner structure of the proton, probing a region of phase space at low Bjorken-x where the other LHC experiments have limited sensitivity. I will also present measurements of cross-section ratios, which can provide precision tests of the Standard Model. I shall also present a measurement of the forward-backward asymmetry (AFB) in Z boson decays to two muons.
This result allows for precision tests of the vector and axial-vector couplings of the Z boson, providing sensitivity to the effective weak mixing angle (sin2(θWeff)). The AFB distribution visible in the LHCb acceptance is particularly sensitive to this angle, as the forward phase-space probed at LHCb means that the initial state quark direction is better known than in the central region probed by the other LHC detectors. This reduces uncertainties in extracting sin^2(θWeff) from A_FB, and allows LHCb to make the most precise determination of sin2(θWeff) at the LHC. I shall also discuss (some of) the future potential of these and related measurements at LHCb.
Grainne wilkinson
Mains water shut down over Easter Vacation
The mains water supply (hot water and cold) will need to be turned off for a couple of days over the Easter vacation. Please let me know as soon as possible if this will cause you problems.
Shonah Ion
Ian Bradley – retirement do
As you may know Ian Bradley is retiring at the end of March. To wish Ian well for the future we’ll be having drinks and nibbles in the Physics Atrium on Friday 24th March at 4 pm.
If you’re intending to come along it would be very helpful indeed if you could let me know by email by Monday 20th.
Grainne Wilkinson
Physics Refurbishment – Weekly Update
Please see below details of scheduled works on the Physics refurbishment project for week commencing Monday 20th February.
- Re-roofing works and cladding – low noise, no vibration
- Scaffold stripping– low noise, low vibration
- New toilet block façade works – medium noise, low vibration
- 2nd fix joinery works – medium noise, low vibration
- Plastering – low noise, low vibration
- Mist coat decoration – low noise, low vibration
- Floor preparation – medium noise, low vibration
- Plant room cladding – medium noise, low vibration
- Brickwork to existing toilet block – medium noise, low vibration
- Lift installation – medium noise, medium vibration
- Suspended ceiling installation – medium noise, minimum vibration
- Floor covering – low noise, no vibration
- Fixed lab benching – medium noise, minimum vibration
Should you have any queries regarding the project please contact the Senior Project Manager, Helen Wood, via the Facilities Helpdesk on facilities.helpdesk@lancaster.ac.uk or 01524 593333.
Charlotte Lapping
April Safety Induction
April’s safety induction will take place on Thursday 6th April at 2:30pm in A27. Any new members of staff or those wanting a refresher please come along.
Shonah Ion
Do you fancy acting as a judge at the IOP’s North West undergraduate Physics Challenge this year?
Derek Ward-Thompson at UCLan has asked me to circulate the invitation to staff here at Lancaster. It’s at Salford University on Wednesday 29th March from 10.30am till 3pm.
If interested, please contact Derek directly (dward-thompson@uclan.ac.uk)
Gráinne Wilkinson & Jim Wild