Calendar

Jan
23
Tue
Colloquium: Darrell Schlom @ 1080 Physics Research Building (Smith Seminar Room)
Jan 23 @ 3:45 pm – 4:45 pm

Speaker: Darrell Schlom

Title: Tuning the Band Structure of Ruthenates with Strain and Dimensionality

Affiliation: Cornell University


Abstract:

Ruthenates with perovskite and perovskite-related structures host a remarkably diverse class of exotic quantum phases ranging from spin-triplet superconductivity, ferromagnetism, metamagnetism, spin-density waves, antiferromagnetism, and quantum criticality—all with the same basic building block of corner-sharing RuO6 octahedra containing Ru4+ ions.  We exploit strain engineering1 to tune the band structure of the complex oxide ruthenates:  CaRuO3,2,3 SrRuO3,3,4 and BaRuO3,5 with the perovskite structure as well as their two-dimensional counterparts Sr2RuO4 and Ba2RuO4.6  The ruthenate films are grown by reactive molecular-beam epitaxy (MBE) and the misfit strain is imposed by underlying substrates to strain these complex oxide thin films to percent levels3—far beyond where they would crack or plastically deform in bulk.  The band structure is revealed by high-resolution angle-resolved photoemission (ARPES) on pristine as-grown surfaces of these complex oxides made possible by a direct ultra-high vacuum connection between the MBE and ARPES.  Our work demonstrates the possibilities for utilizing strain engineering as a disorder-free means to manipulate emergent properties and many-body interactions in correlated materials.

Jan
30
Tue
Physics Colloquium: Samindranath Mitra @ 1080 Physics Research Building (Smith Seminar Room)
Jan 30 @ 3:45 pm – 4:45 pm

Speaker: Samindranath Mitra

Title: Physics After the Lab and the Desk: Your Work in PRL

Description: Physics research takes place mostly at your desk, at the keyboard, in the lab. You communicate results through posters, talks, and papers — leading to, hopefully, wide dissemination and recognition. The sequence entails interacting with journal editors, referees, conference chairs, journalists, and others. I will focus on this post-research collaborative process in physics, now in a state of flux in the age of social media and Google Scholar, primarily through the lens that is Physical Review Letters.

Feb
6
Tue
Physics Colloquium: Tao Han @ 1080 Physics Research Building (Smith Seminar Room)
Feb 6 @ 3:45 pm – 4:45 pm

Speaker: Tao Han

Title: Physics Motivations for Future Colliders

Affiliation: University of Pittsburg

Description: With the milestone discovery of the Higgs boson at the CERN LHC, high energy physics has entered a new era. The Higgs boson is the last member in the “Standard Model” (SM) of particle physics, which describes the physical phenomena at high energies to a very high accuracy. The completion of the Standard Model implies, for the first time ever, that we have a relativistic, quantum-mechanical, self-consistent theoretical framework, valid up to exponentially high energies, perhaps to the Planck scale. Yet, there are compelling reasons, both from observations and from theoretical considerations, to believe that new physics beyond the SM is not far from our reach. I discuss the need for new physics, and motivate the future colliders beyond the LHC to explore the new territory under the “Higgs lamppost”.

Mar
27
Tue
Physics Colloquium: Kenneth Dill @ 1080 Physics Research Building (Smith Seminar Room)
Mar 27 @ 3:30 pm – 4:30 pm

Speaker: Kenneth Dill

Title: How Cellular Decisions are Encoded in it’s Proteome’s Physical Chemistry

Affiliation: Stony Brook University

Description: Some cell behaviors can be explained by the physics of the cell proteome, the full complement of the cell’s proteins.  For example, we believe that heating kills cells by denaturing their proteins.  Salt slows cell growth by overcrowding the proteins.  Oxidative damage in aged cells may involve electrostatic unfolding.  We explore these properties using physical chemical models.  We also explore proteostasis, the machinery that keeps the cell’s proteins folded and disaggregated, particularly under stress.  We find many ways in which evolution has encoded `cleverness’ into proteostasis decision-making.