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
Leave a Comment
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
If you haven't booked your place at today's lunchtime lecture from the @StpDias, exploring the legacy of Schrödinger’s 'What is Life?' lectures and book, do so now at: bit.ly/2KZStSH It's te final one lecture of the series. #DIASdiscovers
Don't miss the 4th and final lecture in our #WhatisLife series with Prof Werner Nahm, Director of @StpDias, looking at ‘Beyond the ‘What is Life?’ lectures and book’. This lecture, at 1pm tomorrow, will explore the legacy of Professor Erwin Schrödinger. bit.ly/2KZStSH
#DidYouKnow the recent earthquake in Donegal was not the county's first? In fact, they're well used to a tremor or 2.7 in the North West. Read about the county's ground shaking history in The @IrishTimes at: bit.ly/2UTkAHw #DIASdiscovers
#OTD John T. Lewis was born in 1932. Lewis served as Director of @StpDias and was described by @IrishTimes as a 'theoretical physicist who revolutionized telecommunication.' You can read his obituary in the @LondonMathSoc newsletter at: bit.ly/2XeTrvn #DIASdiscovers
The @IrishResearch Advanced Laureate Awards are crucial for frontier basic research #LoveIrishResearch #DIASdiscovers twitter.com/IrishResearch/…
The first ever image of a #blackhole as revealed today by @ehtelescope at a press conference at the European Commission. Very historic day for #astrophysics and #theoreticalphysics Delighted to be joined by @Cmdr_Hadfield on this momentous occasion #DIASdiscovers
We are delighted to be joined by @Cmdr_Hadfield here at DIAS today for the screening of the first image of a #blackhole being revealed by @ehtelescope #DIASdiscovers
@siliconrepublic @siliconrepublic. Very exciting news today. We'll be streaming the Press conference live here at HQ. @DIAS_Dublin and @DIASAstronomy professors incl. @petertgallagher are available for comment, should you wish to speak to someone. We're following developments very closely.
Dr. Martin Möllhoff, Director of Seismic Networks at @DIAS_Dublin spoke to @drivetimerte on @RTERadio1 yesterday, about the Earthquake that took place in Donegal on Sunday. Listen back at: bit.ly/2uSHwYf #DIASdiscovers
There has been lot's of coverage of the Donegal Earthquake recorded by the Irish National Seismic Network run by @DIAS_Dublin in @irishexaminer, @beat102103 @breakingnewsie @OceanFmIreland @buzzdotie and this piece from The @IrishTimes - bit.ly/2OZ3Bh5 #DIASdiscovers