Title: Topology of quantum systems out of equilibrium
Speaker: Max McGinley (University of Cambridge)
Abstract: Topological phases of matter have attracted a huge amount of interest in recent years, thanks largely to the discovery of topological insulators in two and three spatial dimensions, amongst other experimental successes. These phases fall outside of Landau’s symmetry-breaking paradigm, and can be understood through some notion of a `twist’ in the ground state wavefunction, partnered with characteristic gapless edge states at their physical boundaries. Through understanding the mathematical structures which encode the ground state wavefunction’s topological properties, it has been possible to exhaustively classify different topological phases in a manner which is sensitive to spatial dimension, symmetries, and the presence/absence of interactions. In this talk, rather than discussing the topological properties of ground states of Hamiltonians, I will consider nonequilibrium states resulting from unitary time evolution. I will demonstrate how the topology of wavefunctions can differ in and out of equilibrium, and provide some simple concrete examples which demonstrate their key phenomenology. Just as in equilibrium, it is possible to construct an exhaustive non-equilibrium classification of topological systems, and I will present this classification for non-interacting fermions with non-spatial symmetries, encompassing the majority of the so-far experimentally realized systems. I will conclude by discussing the direct experimental consequences of our results, including important ramifications for the use of topological zero-energy bound states in quantum information technologies.
Time: Thursday, 11 April 2019, 2:30 pm
Location: Lecture Room, 1st Floor, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4
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Last Updated: 8th April 2019 by George Rogers
Thursday 11th April: STP Seminar – Topology of quantum systems out of equilibrium
Title: Topology of quantum systems out of equilibrium
Speaker: Max McGinley (University of Cambridge)
Abstract: Topological phases of matter have attracted a huge amount of interest in recent years, thanks largely to the discovery of topological insulators in two and three spatial dimensions, amongst other experimental successes. These phases fall outside of Landau’s symmetry-breaking paradigm, and can be understood through some notion of a `twist’ in the ground state wavefunction, partnered with characteristic gapless edge states at their physical boundaries. Through understanding the mathematical structures which encode the ground state wavefunction’s topological properties, it has been possible to exhaustively classify different topological phases in a manner which is sensitive to spatial dimension, symmetries, and the presence/absence of interactions. In this talk, rather than discussing the topological properties of ground states of Hamiltonians, I will consider nonequilibrium states resulting from unitary time evolution. I will demonstrate how the topology of wavefunctions can differ in and out of equilibrium, and provide some simple concrete examples which demonstrate their key phenomenology. Just as in equilibrium, it is possible to construct an exhaustive non-equilibrium classification of topological systems, and I will present this classification for non-interacting fermions with non-spatial symmetries, encompassing the majority of the so-far experimentally realized systems. I will conclude by discussing the direct experimental consequences of our results, including important ramifications for the use of topological zero-energy bound states in quantum information technologies.
Time: Thursday, 11 April 2019, 2:30 pm
Location: Lecture Room, 1st Floor, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4
Category: Regular seminars, School of Theoretical Physics News & Events
...obituaries of prominent individuals The manuscript has been preserved in the @Library_RIA since 1883. (3/3) @HistFest #DIASdiscovers #connacht #books
The Annals of Connacht is a vellum manuscript that was written in the mid-16th century. The contents were derived from older annals compiled for the O’Conors of the Connacht and contain an annual record of significant events over 320 years, and... (2/3)
Date: 19 October 1944 Paper: The Irish Press Synopsis: DIAS has been publishing books since it's founding. One such early publication is the edited manuscript of the Annals of Connacht (Annála Connacht) which was edited for the first time by Martin Freeman of DIAS. (1/3)
This work was to help towards the preservation of the Irish Language, to maintain it's continuity with the past, and was to become a resource for teachers to check pronunciation #DIASdiscovers #Irish #Irishlanguage #CelticStudies #Gaelic
The researchers used the International Phonetic Alphabet, slightly modified to represent vowels and consonants of living speech. At that time there were concerns over the deterioration of the Irish language due to the "overpowering influence of English"
Date: 02 June 1943 Paper: The Irish Press Synopsis: In 1943, a phonetic investigation led by Brian Ó Cuív, Risteárd B. Breathnach and Tomás de Bhaldraithe of DIAS would begin the first systematic scientific recording of the varied sounds of modern Gaelic speech.
Happy Birthday! twitter.com/thecelticist/s…
The papers were 1) Affine Field Theory: conservation identitites and relation to Weyl and Eddington 2)The Union of the three fundamental fields (Gravitation, Menson, Electromagnetism) Which went on to secure worldwide acclaim. #DIASdiscovers
Date: 01 December 1943 Paper: The Irish Press Headline: Two Papers by Dr. Schroedinger Synopsis: 1943 was a busy year for Schroedinger. Not only did he deliver the "What is Life?" Lectures in @tcddublin in February in November he delivered two papers in the @RIAdawson (1/2)
Available to buy on the DIAS bookshop: books.dias.ie/index.php?main… (5/5) #DIASdiscovers #celtic #studies #twopatricks
"In the lives of St. Patrick, the two saints are invariably fused into one", said Prof. O'Rahilly in his lecture. The lecture was a condensation from O’Rahilly’s book “The two Patricks: a lecture on the history of Christianity in fifth-century Ireland”. (4/5)
He was known by his first name Patricius, which in later times would lead to confusion as he was succeeded by another apostle of the same name (Saint Patrick or Patricius in Latin). (3/5)
He spoke on "Palladius and Patrick". Palladius was the first bishop of the Christians of Ireland. (2/5)
Date: 21st March 1942 Paper: The Irish Press Headline: Palladius and Patrick | School Of Celtic Studies Lecture Synopsis: The first public lecture under the auspices of the School of Celtic Studies was delivered in Trinity College by Professor T. F. O'Rahilly in 1942. (1/5)
As part of our ongoing participation in the @HistFest we decided to take a look into the Irish Newspaper Archives and see where DIAS made it into print over the last 80 years. There were so many articles, the hardest part was selecting what we would post. We hope you enjoy!
@AReillyFailte @CultureNight @VisitDublin Thanks Antoinette! Glad you enjoyed 😊