Title: Quantum Correlations in Space & Time
Speaker: Joe Fitzsimons (Singapore University of Technology and Design)
Abstract: In ordinary, non-relativistic, quantum physics, time enters only as a parameter and not as an observable: a state of a physical system is specified at a given time and then evolved according to the prescribed dynamics. While the state can, and usually does, extend across all space, it is only defined at one instant of time, in conflict with special relativity where space and time are treated on an equal footing. In this talk, I will examine the consequences of extending the notion of the quantum density matrix to multiple spatial and temporal measurements. To this end, I will introduce the concept of a pseudo-density matrix which treats space and time indiscriminately. This matrix in general fails to be positive for timelike separated measurements, motivating the definition of a measure of causality that discriminates between spacelike and timelike correlations. I will present the results of recent NMR experiments to measure causal correlations and their decay under the effects of noise. In the second half of the talk, I will present an application on the pseudo-density framework to bounding the capacity of quantum channels, and show how it can be used to obtain new bounds for the capacity of shifted depolarizing channels.
Time: Tuesday 6th March 2018, 2.30pm.
Place: Lecture Room, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4.
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Last Updated: 23rd May 2018 by George Rogers
Tuesday 6th March: STP Seminar – “Quantum Correlations in Space & Time”
Title: Quantum Correlations in Space & Time
Speaker: Joe Fitzsimons (Singapore University of Technology and Design)
Abstract: In ordinary, non-relativistic, quantum physics, time enters only as a parameter and not as an observable: a state of a physical system is specified at a given time and then evolved according to the prescribed dynamics. While the state can, and usually does, extend across all space, it is only defined at one instant of time, in conflict with special relativity where space and time are treated on an equal footing. In this talk, I will examine the consequences of extending the notion of the quantum density matrix to multiple spatial and temporal measurements. To this end, I will introduce the concept of a pseudo-density matrix which treats space and time indiscriminately. This matrix in general fails to be positive for timelike separated measurements, motivating the definition of a measure of causality that discriminates between spacelike and timelike correlations. I will present the results of recent NMR experiments to measure causal correlations and their decay under the effects of noise. In the second half of the talk, I will present an application on the pseudo-density framework to bounding the capacity of quantum channels, and show how it can be used to obtain new bounds for the capacity of shifted depolarizing channels.
Time: Tuesday 6th March 2018, 2.30pm.
Place: Lecture Room, School of Theoretical Physics, DIAS, 10 Burlington Road, Dublin 4.
Category: News, Regular seminars, School of Theoretical Physics News & Events, Seminars
#DidYouKnow that we have repository of research publications showcasing the research of our professors, staff and scholars at DIAS? From academic papers, to technical reports, you can access it at: bit.ly/2V9GL87 #DIASdiscovers
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DIAS iMARL infrastructure deploying ocean bottom seismometers which detect earthquakes and major weather events, track the presence of whales and dolphins, and capture seabed images. #DIASdiscovers
Great article in today's @IrishTimes about the breakthrough in understanding #SolarStorms, that was made by DIAS in conjuction with @tcddublin and @helsinkiuni. Read it at bit.ly/2Nd86ne. #DIASdiscovers
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A key priority of the @SCSLibrary is the provision of reliable editions of hitherto unpublished material and texts, previously accessible only to scholars consulting the manuscripts. Learn more about the @DIAS_ISOS project at isos.dias.ie #DIASdiscovers
. @ProfBrianCox & @robinince using coffee & cream to explain how we got from the Big Bang to the universe as we know it today. Fantastic show tonight in @3ArenaDublin - masterclass in communicating complex scientific concepts effectively
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“Your theory suggests there was a day without a yesterday” - Lemaître’s comment to Einstein on the Theory of Relativity, as cited by @ProfBrianCox
“9000 people have come out on a Saturday night to chat about #Cosmology - that makes me feel good about the world” - @ProfBrianCox is pleased with the turnout for his Dublin show :)
We’re excited to be @3ArenaDublin tonight for @ProfBrianCox. We know he’s a big fan of #Schrödinger, first Director of @StpDias, so looking forward to seeing if he speaks of Schrödinger‘s time in Dublin...