The "ultracold" part of the Midlands Physics Alliance targets cutting-edge interdisciplinary research at the rapidly evolving interface between cold atom, condensed matter, and optical physics. It joins more than 15 research groups in theoretical and experimental cold atom physics in a strategic partnership between the Universities of Birmingham, Nottingham, and Warwick. more...
Published: smoothing out the quantum roughness of light
At the quantum level, the intensity of light is quantised and fluctuates. This is because a beam of light is in fact a stream of particles, the photons. The randomness of the photon distribution inside the beam leads to noise when the energy of the beam is detected: this is the so-called shot noise. Physicists have been routinely controlling the fluctuations of a full beam of light, but the quantum fluctuations are present at all spatial scales in the beam and controlling these locally has proved to be a challenge. Using light and an atomic vapour, we have produced a light field which exhibits reduced quantum fluctuations at all points of its transverse profile, as if the quantum roughness had been smoothed out. This kind of light, when used to illuminate objects in optical set-ups, should lead to improved resolution in certain imaging schemes.
The research has been published in Physical Review X [PRX].
iSense - Atom interferometry outside the lab
Congratulations to the iSense team, who have successfully taken their apparatus to Brussels and demonstrated atom interferometry to the iSense consortium and the EU commission. This was the final progress review and the project is now officially over. The iSense prototype will continue its life as a testing platform and we will keep improving its capabilities to turn it into a reference instrument.
Top: the iSense team next to the prototype in the University of Birmingham Brussels office.
Bottom: atom interference fringes obtained in the lab in Birmingham and in in the office in Brussels.
The iSense movie is out!
iSense is a European project aiming to develop quantum technologies based on cold atoms. With the project nearing completion, this documentary explores the motivations behind the development of quantum technologies, looks back at the progress accomplished, and dives into the future of cold-atom quantum technologies.
On the BBC: GGtop archaeologists realise best mapping ever of Stonehenge
In a documentary to be aired on the BBC, an international team of archaeologists, including Prof. Vince Gaffney's group from the University of Birmingham, present their latest findings about the hidden landscape of Stonehenge. Using the latest surveying technologies, the team was able to reveal what lies beneath the surface and discover and map many previously unknown monuments. Vince is also part of the GGtop project and is seeking to develop gravimetry as an additional method of mapping the underground. If you look closely in the background of this video clip, you can see the GGtop team performing the first gravity measurement within the Stonehenge landscape!
Published: Bloch oscillations of cold atoms in a ring cavity
Our theoretical work on the backaction-driven dynamics of cold atoms in a high-finesse ring cavity has been published in Physical Review Letters [PRL, arXiv]. A constant force applied to an object usually leads to a constant acceleration and ultimately to a displacement. However since the work of Felix Bloch in the 20s, we know that low-energy particles placed in a periodic potential and subject to an additional constant force oscillate instead of propagating. We have considered the case where the potential is created by laser light in a high-finesse optical cavity and the particles are cold atoms strongly coupled to the light. We have shown that the oscillations of the atoms alter the propagation of the light and modify the potential in such a way that for the right choice of parameters a net displacement occurs. The transport speed and direction can be controlled via the detuning between the laser and the cavity. Our results add to the cold atoms quantum simulation toolbox, with implications for quantum sensing and metrology.
From the lab: collective strong coupling of potassium atoms in a ring cavity
We have achieved collective strong coupling of atoms and light in a high-finesse ring cavity. This is observed as a splitting of the cavity transmission spectrum in the presence of atoms, known as the vacuum Rabi or normal-mode splitting. Normal-mode splitting is observed when coherent coupling overwhelms damping and dephasing. We will use techniques from quantum nonlinear optics to build a novel laser sensor with cold atoms as the gain medium.
The blue data show the spectrum for an empty cavity, and red data show the effect of the presence of some 10s of thousands of cold potassium atoms.
Quantum technology transfer between MUARC and M Squared Lasers
A Knowledge Transfer Secondment has been established between MUARC and the company M Squared Lasers in Glasgow. Starting from September, Komal Pahwa, a PhD student of MUARC, is helping M Squared to develop laser and electronic systems for cold-atom-based sensors. The partnership will lead to a new generation of commercial quantum sensors.
Dr Nils Hempler, head of Innovation, Dr Graeme Malcolm, CEO, and Komal Pahwa in front of the first cold atom set-up in a UK company.
Prof. Chris Rogers on GGtop and future cities
In this interview Prof. Chris Rogers, leader of Mapping the Underworld project, explains the crucial role that gravity-mapping technologies such as GGtop will play in the design of tomorrow's cities. By promoting unprecedented collaboration between quantum scientists and civil engineers, the GGtop project develops some of the tools that will facilitate the creation of more sustainable urban environments.
Quantum technologies on display at ICT 2013
The iSense and GGtop projects, both led by MUARC, were showcased at the ICT 2013 conference in Vilnius, 6-8 November 2013. The cold atom demonstrator drew crowds as the information and communication technology community was keen to learn about laser cooling and how the use of matterwaves can make better sensors. This was a great way to show that cold atoms are not confined to laboratories any more and that the technology is ready to be used in the field.
Visitors of ICT 2013 gather around the iSense cold atom demonstrator to check the "coolest place in Vilnius."
First cold atoms in iSense
The iSense team in Birmingham reports on the creation of a magneto-optical trap (MOT) of Rubidium atoms using a low power atom chip designed and built at the University of Nottingham. This is the first step towards creating a compact gravity measurement device.
The atoms are trapped in a mirror MOT configuration using four laser beams, two of which are reflected from the chip surface. The magnetic fields are generated inside the chamber by the chip assembly.
In the next stage we will integrate compact lasers and electronics from our European partners. Upon completion, iSense will produce atom interferometry signals to measure gravity in the field.
Left: trapped atoms fluorescing and their reflection from the chip surface. Right: the iSense vacuum chamber featuring the gold-coated atom chip assembly.
MPAGS Summer School (Sept 2013)
For the second time, the Midlands Physics Alliance Graduate School (MPAGS), in collaboration with the University of Granada, is organizing a summer school that will be held in Granada, Spain, 15-19 September 2013.
This School, "Quantum Matter: Foundations and Applications", will feature tutorial-style lectures introducing themes of broad interest in the areas of cold atoms and molecules, quantum optics and condensed matter physics, quantum information and quantum interference and precision measurements.
Apply online. Application deadline is 30 June.
Bose-Einstein condensation of Rubidium
The team of the "disorder" experiment has achieved the Bose-Einstein condensation of Rubidium in their combined-species Rubidium-Potassium apparatus. The condensate was obtained after magnetically transporting a cloud of laser-cooled atoms in a science cell, and performing evaporative cooling first in the magnetic trap and then in a light dipole trap. The pictures below show the anisotropic expansion of the condensate. The thermal cloud, seen as a halo, expands isotropically.
Next steps will be to include fermionic Potassium and to study the combined dynamics in arbitrary two-dimensional potentials.
- Absorption images of the condensate after increasing expansion times.
GG-TOP takes on mineral exploration
Young Atom Opticans conference in Birmingham (YAO 2013)
8th April 2013 to 12th April 2013
YAO is a yearly conference whose main goal is to create an international society of young scientists who specialize in quantum optics with a special focus on cold atomic gases. During these meetings experimentalists as well as theorists have a chance to present their research and results while also taking part in thought provoking discussions on their topics, whether it be in the form of a short presentation or a poster during the poster session. The participants of this conference are usually young doctoral students, but the conference is also open to masters students or really any young scientist who are beginning their work in the field of atomic physics. Apply here before Friday 22 February 2013.
Achievement of Bose-Fermi mixtures in a magneto-optical trap
In the context of the Quantum Simulator project, the first magneto-optical trap for rubidium and potassium in the Quantum Matter group has beeen realised. The atoms are first trapped in a 2-dimensional magneto-optical trap to create a cold atom beam and then transferred by a pushing beam into another vacuum chamber where both species are retrapped by a six beam magneto-optical trap.
- Fluorescence image of a Potassium 40 magneto-optical trap.
Published: potassium spectroscopies for laser frequency stabilization
Our work on sub-Doppler polarization spectroscopy and magnetic dichroism (ie, DAVLL) of potassium has been published in Optics Express [Opt. Exp. 20, 17456 (2012), arXiv:1205.0459]. The focus is on frequency-stabilizing lasers for experiments with cold atoms. This is a companion piece to our earlier work using modulation spectroscopy [J. Phys. B 45, 065002 (2012), arXiv:112.4998]. We plan to use our modified form of magnetically-induced dichroism in our experiment with cold atoms in a high-finesse ring cavity.
First 2D- and 3D-MOT with Strontium achieved! (June 2012)
Magneto-optical traps (MOT) in a high vacuum environment require a bright source of pre-cooled atoms. For Strontium, the standard technology is an atomic beam slowed down by laser from a hot oven. For the Strontium clock at Birmingham, we have implemented an alternative technology, borrowed from experiments which use alkaline atoms: a 2-dimensional magneto-optical trap which produces a stream of collimated atoms at one end of the trap. The magnetic quadrupole field is produced by permanent magnets, in a bid to reduce power consumption and increase portability.
Magnetic field of the 2D MOT (left) and fluorescent of the 3D MOT (right).
MUARC and MPAGS Summer School (Sept 2011)
The MUARC & MPAGS summer school on Quantum Matter: Foundations and New Trends will take place this year in Granada, Spain, on 18-22 September 2011. The school will provide a basis for new members of the community and deepen the knowledge of more experienced ones in the areas of quantum gases, quantum optics and condensed matter physics. Registration opens 31st March.
PhD positions now open in Birmingham
We have positions to work on two exciting European projects, the "space optical clock" and the "integrated quantum sensor". More details on our jobs section.
MUARC Summer School (August 2010)
The MUARC summer school on Advanced Techniques in Atomic Physics will take place in Ardencote, near Birmingham, UK, on 22-27 August 2010. The school is intended to enable advanced graduate students or early post-docs to target the next step in their career. Registration is now open.
MUARC/MAPGS winter school (Dec 2009)
The joint MUARC/MPAGS winter school for advanced undergraduates and starting graduate students was held at the University of Nottingham on 13-15th December. The programme covered a broad range of topics currently investigated at MUARC such as quantum optics, quantum simulations with Rydberg atoms, atom chips, and quantum gases in optical lattices.
The next school will be held in August 2010 and will target advanced postgraduate students and young researchers.
Two new lecturers to join the Midlands Ultracold Atom Research Centre (1 Aug 2009)
Lucia Hackermüller and Jon Goldwin are joining MUARC. Lucia will be a Lecturer at the University of Nottingham and will study Lithium-Caesium cold molecules on an atom chip. Jon will be a Lecturer at the University of Birmingham and will study the interaction of ultracold fermionic Potassium with a single quantum optical field in a high-finesse cavity.
Openlab party at Birmingham (26 March 2009)
The openlab party celebrated the end of the refurbishment of the Cold Atom labs in Birmingham.