AtMol Research Seminar Archive
Index Current Seminars

Unless otherwise advertised, all talks are in room Ph30 at 1:00pm on Wednesdays.

Easter Term 2014

Date Speaker Institution
Journal Club - Quantum Biology
Wed 30 April 2014 Kate Whittaker Durham University

There is a growing amount of evidence that nature is able to use quantum effects for it’s own advantage [1]. For example, the ability of birds and other animals to sense magnetic fields is common knowledge, but the mechanism behind it is still unknown. There has been a strong case made that European robins use a coherence between radical molecule pairs as an inclination compass [2]. In this talk we will explore both of these phenomena and the associated behavioural and theoretical studies.

[1] Lambert et al. Nature Physics 9 10 (2013)
[2] Schulten et al. Z. Phys. Chem. 111, 15 (1978)

Superconducting nanocircuits for quantum computing and quantum metrology
Wed 7 May 2014 Yuri Pashkin Lancaster University

Superconducting materials are a natural choice for building solid-state quantum circuits, since superconductivity offers coherence. Superconductors have a region in the energy spectrum, in which only one energy level exists, the Fermi level, while all other energy levels are separated from it by the superconducting energy gap. Cooper pairs of conducting electrons condense to this energy level, which appears to be protected from low-energy excitations because of the presence of the gap. This allows to prepare, control and manipulate quantum states in superconductor-based nanostructures for the use in various devices whose operation is based upon quantum principles. In my presentation, I will cover several experiments in which superconducting nanocircuits with a charge degree of freedom were used as solid-state qubits [1,2] and charge pumps [3]. I will also outline the plans of my group to investigate hybrid devices in which mechanical degrees of freedom are strongly coupled to the superconducting condensate.

[1] Y. Nakamura, Yu.A. Pashkin, and J.S. Tsai, Nature 398, 786 (1999).
[2] Yu.A. Pashkin et al., Nature 421, 823 (2003).
[3] J.P. Pekola et al., Rev. Mod. Phys. 85, 142 (2013).

Additional Seminar - Entanglement Control via Geometric Phase
Mon 12 May 2014 Supurna Sinha Raman Research Institute

The talk concerns a polarised intensity interferometry experiment realization based on a theoretical proposal for measurement of the nonlocal Pancharatnam phase acquired by a pair of Hanbury Brown-Twiss photons. The setup involves two polarised thermal sources illuminating two polarised detectors. Varying the relative polarisation angle of the detectors introduces a two photon geometric phase. This sheds light on control of entanglement via the geometric phase.

Wed 14 May 2014 Neal Radwell University of Glasgow

Manipulating the dimensionality of molecule-based magnets
Wed 21 May 2014 Tom Lancaster Durham University

Although the solid state provides many examples of model quantum systems, the role of disorder and the details of atomic-scale chemistry hinder our ability to control the crucial parameters in any systematic way. Molecule-based magnets are materials whose principal structural building blocks are organic molecules, and they embody a quantum component (transition metal ions in well-defined geometries) coupling via a flexible and highly tunable organic framework. Here I will discuss examples of where we have been able to tune the dimensionality of a magnetic system, allowing us to tune from cases in which magnetic interactions are constrained to act within a plane, to those where they act along a chain, to those where they act within effectively zero-dimensional clusters.

Quantum memories for light based on Raman scattering
Wed 28 May 2014 Joshua Nunn Oxford University

Quantum technologies could revolutionise computing, communications, and sensing. Optics is a powerful platform for processing quantum information, since optical modes are noise-free at room temperature; can be manipulated with cheap passive components; can be carried over long distances in free space and in fibres; and can carry THz bandwidths. But logic operations with photons are inherently probabilistic, so that the technology cannot be scaled up without a multiplexing strategy to actively synchronise components. We have developed quantum memories based on Raman scattering that enable the coherent storage and on-demand retrieval of photons. I will discuss progress towards the goal of using Raman memories to enable large-scale quantum photonic processors.

Journal Club Talk - Magnetic monopoles and why they can get your head in a spin
Wed 4 June 2014 Robert Bettles Durham University

In 1931 Dirac [1] showed that the existence of an isolated magnetic charge or ‘magnetic monopole’ would have many fundamental implications for our understanding of nature, explaining for example why electric charge is quantised. Since then the experimental search for magnetic monopoles has produced a few tantalising but as yet inconclusive monopole sightings. In my talk however I will present two recent experiments that claim to have observed monopoles, one in a condensed matter spin-ice lattice [2] and another in a spinor B.E.C. [3], and discuss whether or not these are indeed true magnetic monopoles.

[1] Dirac Proc. Roy. Soc. A 133, 60 (1931)
[2] Morris et al. Science 326, 411 (2009)
[3] Ray et al. Nature 505, 657 (2014)

Wed 11 June 2014 - 13:00-13:45 Erwan Bimbard Institut d'Optique, Paris

Abstract TBC

SEMINAR IN PH8 - Photoassociation spectroscopy of ultracold YbRb in a MOT and in a conservative trap
Wed 11 June 2014 - 14:30-15:15 Axel Görlitz Heinrich-Heine-Universität Düsseldorf

Abstract TBC

1st Year Talk - Title TBC
Wed 18 June 2014 Philip Gregory Durham University

Abstract TBC

1st Year Talk - Moving Magnetic Trap Decelerator: Progression of the Decelerator Stage
Wed 25 June 2014 Lewis McArd Durham University

Properties and applications of cold and ultracold molecules is a topic of ever increasing popularity. An example of a technique to achieve such temperatures is the Zeeman decelerator. This makes use of the potential experienced by molecules in an inhomogeneous magnetic field. The efficiency, however, is fairly limited. One solution to this is to reconsider how the magnetic fields are used to decelerate. The form of Zeeman decelerator discussed in this talk traps molecules in a 3D trap which is then decelerated along with the captured molecules. Trapping is achieved using a combination of flattened helical coils and a quadrupole guide. In this talk I will discuss the progress made in the decelerator stage over the last nine months. This will focus mainly on the coil fabrication and the design of the high current electronics required for our decelerator.

TUESDAY SEMINAR A Quantum Boost for Atomic Sensors
Tue 8 July 2014 Simon Haine Durham University

Atom interferometers are devices that exploit the wave-like nature of atoms to make ultra-precise measurements of rotations, accelerations, and gravitational fields. The sensitivity of these devices is ultimately limited by quantum noise. I will discuss a variety of schemes for using quantum tricks to enhance the sensitivity of these devices beyond the standard quantum limit.

To change details on this page please contact Rob Bettles.