Theoretical Physics

Search site


Physics & Astronomy
Latest News

New paper in Nature Communications on exchanging Majorana zero modes

31 October 2016

Nature Communications 7, Article number: 13194 (2016)

 

Experimental Simulation of the Exchange of Majorana Zero Modes

 

Majorana zero modes are an eagerly anticipated resource for quantum information processing as they offer immunity to noise, but they are difficult to create and control experimentally. In collaboration with theorists and experimentalists from Hefei University of Science and Technology in China, Dr Jiannis Pachos from the Theoretical Physics Group in Leeds demonstrated in a recent publication in Nature Communications a fundamental property of Majorana fermions: their non-trivial statistics. This was performed with a quantum simulation of a superconducting chain with linear optics. This system provided the degree of controllability that enabled the manipulation of Majorana quasiparticles and the demonstration of their anyonic statistics. A popular version of the article has been published in 2Physics.




2016: The Year of Topology in Condensed Matter Physics

19 October 2016

Read about Nobel Prize in Physics 2016 and how it relates to our research.

This year two of the most important physics prizes have been awarded to pioneers of topology in condensed matter physics. The 2016 Nobel Prize for Physics was divided between David Thouless, Duncan Haldane and Michael Kosterlitz for “Theoretical Discoveries of Topological Phase Transitions and Topological Phases of Matter”, while the Oliver Buckley Condensed Matter Physics Prize went to Alexei Kitaev and Xiao-Gang Wen for “Theories of Topological Order and its Consequences in a Broad Range of Physical Systems”

Read more




New paper in Physical Review Letters

11 October 2016

"Power-Law Entanglement Spectrum in Many-Body Localized Phases", Maksym Serbyn, Alexios A. Michailidis, Dmitry A. Abanin, and Z. Papic, Phys. Rev. Lett. 117, 160601 (2016).

Efficiently simulating many-body localisation

The amount of quantum entanglement in a many-body wave function determines whether it can be efficiently compressed and encoded by a small number of classical parameters. Ground states of many-body systems are known to have low entanglement, and can be efficiently simulated by the so-called "matrix product states" -- the property which underlies the success of the density-matrix renormalisation group.

In a new paper published in Phys. Rev. Lett., the authors characterise the entanglement of highly excited states in many-body localised (MBL) systems by studying its "entanglement spectrum". MBL phases have been a subject of much recent interest as phases of matter that break ergodicity and thus avoid thermalisation. The paper argues that the entanglement structure of MBL states, while different from ground states, still allows for compact parametrisation by matrix product states. An efficient algorithm is developed to obtain highly excited states of large MBL systems. This work opens a door for studying a broad class of disordered quantum systems, inaccessible by other techniques. It is expected that the new algorithm will also give a much-needed insight into the nature of the transition between MBL and ergodic (thermal) phases.

journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.160601




Royal Society Meeting: Breakdown of Ergodicity in Quantum Systems

15 September 2016

Scientific discussion meeting organised by Professor Sir Michael Pepper FRS, Dr Arijeet Pal, Dr Zlatko Papic, Dr Ulrich Schneider and Professor Steven Simon

Ergodic systems lie at the heart of statistical physics since they reach thermal equilibrium and 'forget' their initial conditions, thereby allowing for coarse-grained classical descriptions. Recently, non-ergodic quantum many-body systems, which fail to thermalise and decohere completely, came into focus. This interdisciplinary meeting will address their fundamental challenges and experimental realisations, including many-body localisation and other novel, non-classical long-time behaviour. 

 

Register here




Sarah Harris published paper in Nature Communications

19 May 2016

Dr Sarah Harris who leads the Computational Biophysics group has published a paper entitled "Structural diversity of supercoiled DNA" in Nature Communications.

The article's reference is:

Rossitza N. Irobalieva, Jonathan M. Fogg, Daniel J.Catanese Jr, Thana Sutthibutpong, Muyuan Chen, Anna K. Barker, Steven J. Ludtke, Sarah A. Harris, Michael F. Schmid,    Wah Chiu & Lynn Zechiedrich. Nature Communications 6, Article number: 8440

It can be accessed here




Displaying results 6 to 10 out of 46