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Colloquia This Term

ics Special Colloquium


Wednesday, January 15, 2020
3:30 PM
Physics Building, Room 204
Note special date.
Saso Grozdanov [Host: Peter Arnold]
MIT
"The holographic view on transport in strongly interacting plasmas"
ABSTRACT:

Microscopic quantum interactions between elementary particles control transport in macroscopic states of matter, such as in fluids and plasmas. In numerous states of interest, these microscopic interactions are strong, including in water, among electrons in graphene and in quark-gluon plasma — a state of nuclear matter that filled the early Universe and that is currently being recreated in particle colliders. While macroscopic theories describing the dynamics of such states, in particular, hydrodynamics (of fluids) and magnetohydrodynamics (of magnetized plasmas) have been partially understood, a full description of transport also requires a certain microscopic knowledge of its underlying quantum physics. After more than a century of striking advance in quantum theories, our theoretical understanding of these microscopic processes remains mostly limited to states with weak interactions. Recently, however, string theory also enabled explorations of strongly interacting states through the mathematical statement of holographic duality, which translates otherwise intractable problems into simpler analyses of black holes and gravitational waves.   

In my talk, I will first discuss new aspects of the macroscopic theory of hydrodynamics, focusing on the properties of the infinite series of higher-order corrections to the infamous Navier-Stokes equations. By using a novel concept of generalized global symmetries, which can encode the fact that the number of magnetic flux lines in Nature is conserved, I will then describe the construction of a new, comprehensive theory of magnetohydrodynamics. This reformulation has led to a number of general theoretical and experimental predictions for transport in magnetized plasmas. I will then move on to discuss the microscopic physics responsible for transport in strongly interacting states. Beginning with an introduction of holographic duality, this section will summarize holographic insights into the problem of the “unreasonable effectiveness of hydrodynamics” for the description of quark-gluon plasma. Then, I will discuss how the descriptions of microscopic physics and transport transition between strongly and weakly interacting pictures. Finally, by utilizing the mathematical structure behind our new theory of magnetohydrodynamics, a holographic dual of magnetized plasmas will be presented along with the first analyses of strongly interacting magnetized transport.

ics Colloquium
Friday, January 17, 2020
3:30 PM
Physics Building, Room 204
RESERVED
ics Special Colloquia


Wednesday, January 22, 2020
3:30 PM
Physics Building, Room 204
Note special date.
Duff Neill [Host: Peter Arnold]
Los Alamos National Lab
"Quantum Open Systems and Field Theory"
ABSTRACT:

When learning about the properties of a quantum mechanical system, for instance, the energy levels of its bound states, it is useful to think of the system as closed and isolated from any environment, though we know in any laboratory setting, all systems eventually will interact with an environment. However, we can often engineer such interactions to be weak, short-ranged, and controllable, so that the isolated approximation is a good one.

I will argue that in many physically relevant field theories, the long-time observables or states of the theory can only be defined in the context of a quantum open system, where we take into account the interactions between the system and the environment continually in the evolution of the system. This is because excitations of the field theory will inevitably create their own environment, that is, states we must trace over. Resumming these interactions with the self-created environment is necessary to give a convergent expansion for observables over all of phase-space.

ics Colloquium
Friday, January 24, 2020
3:30 PM
Physics Building, Room 204
Kent Yagi [Host: Bob Jones]
University of Virginia - Department of Physics
"What do we learn about gravity & nuclear physics from gravitational waves?"
ABSTRACT:

A hundred years after the prediction by Einstein, gravitational waves were directly detected for the first time in 2015 by LIGO, which marked the dawn of gravitational-wave astronomy. Gravitational waves are sourced by astrophysical compact objects, such as black holes and neutron stars. Due to their extremely large gravitational field and compactness, they offer us natural testbeds to probe strong-field gravity and dense matter physics. In this talk, I first give an overview of the current status of gravitational-wave observations. Next, I explain how well one can test General Relativity, constrain the equation of state of nuclear matter and measure nuclear parameters with gravitational waves. I also comment on how one can combine gravitational-wave information with the recent measurement of a neutron star radius by an X-ray payload NICER to further probe nuclear physics.

ics Special Colloquium


Wednesday, January 29, 2020
3:30 PM
Physics Building, Room 204
Note special date.
Gilly Elor [Host: Peter Arnold]
University of Washington
"TBA"
ABSTRACT:

TBA

ics Colloquium
Friday, January 31, 2020
3:30 PM
Physics Building, Room 204
RESERVED
ics Special Colloquium


Wednesday, February 5, 2020
3:30 PM
Physics Building, Room 204
Note special date.
Julian Heeck [Host: Peter Arnold]
University of California, Irvine
"TBA"
ABSTRACT:

TBA

ics Colloquium
Friday, February 7, 2020
3:30 PM
Physics Building, Room 204
RESERVED
ics Special Colloquium


Wednesday, February 12, 2020
3:30 PM
Physics Building, Room 204
Note special date.
Christoph Uhlemann [Host: Peter Arnold]
Univeristy of Michigan
"TBA"
ABSTRACT:

TBA

ics Colloquium
Friday, February 14, 2020
3:30 PM
Physics Building, Room 204
RESERVED
ics Special Colloquium


Wednesday, February 19, 2020
3:30 PM
Physics Building, Room 204
Note special date.
Mohamed Anber [Host: Peter Arnold]
Lewis & Clark University
"TBA"
ABSTRACT:

TBA

ics Colloquium
Friday, February 21, 2020
3:30 PM
Physics Building, Room 204
RESERVED
ics Colloquium
Friday, February 28, 2020
3:30 PM
Physics Building, Room 204
Available
ics Colloquium
Friday, March 6, 2020
3:30 PM
Physics Building, Room 204
Available
ics Colloquium
Friday, March 13, 2020
3:30 PM
Physics Building, Room 204
Available
ics Colloquium
Thursday, March 19, 2020
3:30 PM
Physics Building, Room 204
Note special date.
Andrey Koryatov [Host: Craig Group]
University of Florida
"All about Higgs: an experimentalist's take on what we know and are still to learn"
ABSTRACT:

TBA

ics Colloquium
Friday, March 20, 2020
3:30 PM
Physics Building, Room 204
Reserved
ics Colloquium
Friday, March 27, 2020
3:30 PM
Physics Building, Room 204
Available
ics Joint Astronomy/NRAO


Friday, April 3, 2020
3:30 PM
Physics Building, Room TBD
Note special room.
Prof. Slavko Bogdanov [Host: Kent Yagi]
Columbia University
"TBA"
ABSTRACT:

TBA

ics Colloquium
Friday, April 10, 2020
3:30 PM
Physics Building, Room 204
Hossein Sadegapor [Host: Israel Klich]
Harvard University
"TBA"
ABSTRACT:

TBA

ics Colloquium
Friday, April 17, 2020
3:30 PM
Physics Building, Room 204
Ashot Gasparian [Host: Nilanga Liyanage]
North Carolina A&T State University
"TBA"
ABSTRACT:

TBA

ics Colloquium
Friday, April 24, 2020
3:30 PM
Physics Building, Room 204
Kai Liu [Host: Seunghun Lee]
Georgetown University
"Magneto-Ionics and Chiral Spin Textures"
ABSTRACT:

The coming end of Moore’s law underscores the need for transformative new approaches beyond the complementary metal-oxide semiconductor (CMOS) technology. Nanomagnetics and Spintronics offer an exciting new paradigm to address this grand challenge. For example, magneto-ionic approaches for modifying ion distributions in metal/oxide heterostructures offer exciting prospects to control material properties. Recently, we have demonstrated that such magneto-ionic effect, even though initiated at metal/oxide interfaces, can extend deep into the rest of the oxide films and drastically tailor their physical properties, including antiferromagnetism [1,2], ferromagnetism [3] and superconductivity [4]. Another promising area is novel spin textures such as magnetic skyrmions and chiral domain walls, which offer great potentials for low dissipation magnetic information storage. We have recently demonstrated the realization of room temperature artificial Bloch skyrmion lattices in their ground state [5]. We have also observed a surprising interfacial Dzyaloshinskii–Moriya interaction in systems without the presence of heavy metals [6,7]. These results show promise towards future spin-based nanoelectronics and information storage. Support from the NSF (DMR-1610060, ECCS-1611424, DMR-1905468, ECCS-1933527) and nCORE SMART center is gratefully acknowledged.

 

1. Gilbert, et al. Nature Commun. 7, 11050 (2016).

2. Gilbert, et al. Nature Commun. 7, 12264 (2016).

3. Gilbert, et al. Phys. Rev. Mater. 2, 104402 (2018).

4. Murray, et al, ACS Appl. Mater. Interfaces, DOI: 10.1021/acsami.9b18820 (2019).

5. Gilbert, et al. Nature Commun. 6, 8462, (2015).

6. Yang, et al. Nature Mater., 17, 605 (2018).

7. Chen, et al, submitted.

Colloquia and Special Lectures Committee
Brad Cox (Chair)
P.Q. Hung (Member)
Israel Klich (Member)
Seunghun Lee (Member)
Peter Schauss (Member)
Jeffrey Teo (Member)
Marija Vucelja (Member)

To add a speaker, send an email to bbc2x@Virginia.EDU Include the seminar type (e.g. Colloquia), date, name of the speaker, title of talk, and an abstract (if available). [Please send a copy of the email to phys-speakers@Virginia.EDU.]