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Meetings & Workshops

  1. APR

    25

    Tuesday

    Brookhaven Women in Science (BWIS) Lecture

    "What Women in STEM Can Learn from Polymeric Hydrogels"

    Presented by Surita Bhatia, Stony Brook University

    4 pm, Hamilton Seminar Room, Bldg. 555

    Tuesday, April 25, 2017, 4:00 pm

    The ability to create synthetic materials that mimic the structural and mechanical properties of native tissues, like skin and fibrous tissues, is crucial for many biomaterials applications. Unfortunately, design of such materials remains a significant challenge. Many native tissues and synthetic soft biomaterials are comprised of polymer networks. What are the minimum properties that must be build into a synthetic polymer network in order to reproduce the properties of native tissues? Dr. Bhatia will discuss this issue, while drawing parallels between lessons learned from design of soft materials and challenges faced by women in science and engineering fields.

  2. APR

    28

    Friday

    Condensed-Matter Physics & Materials Science Seminar

    "Magnetometry Study of Underdoped Cuprate YBa2Cu3O6.55"

    Presented by Fan Yu, University of Michigan

    11 am, Bldg. 734, ISB. Conf. Rm. 168

    Friday, April 28, 2017, 11:00 am

    Hosted by: '''''''Qiang Li'''''''

    This talk would be focused on my study of the phase diagram of underdoped cuprate YBa2Cu3O6.55 using torque magnetometry as well as my exploration of extending magnetometry method into even higher magnetic fields (>45T) using pulsed magnet. The complex phase diagrams of cuprates are sometimes referred to as "competing orders", where a large variety of ordering tendencies are known to (co-)exist. Our experiment managed to reveal an anomaly on the magnetic susceptibility, which we believe was related to charge density wave transition. Particularly interesting is that this anomaly is observed in the strong diamagnetic regime where vortex liquid exists. We believe this should be considered as a direct experimental evidence for the picture of "competing orders". To further our understanding of the quantum vortex liquid, experiments at mK temperatures and at magnetic field exceeding 40 Tesla are necessary. During my PhD study, considerable amount of time was devoted to developing a reliable magnetometry method utilizing the pulsed magnet at NHMFL, Los Alamos. I would like to present my trail-and-error as well as the proposition of "time-delayed probe design", which should be able to bypass the inherent noise of a pulsed environment.

  3. APR

    28

    Friday

    Condensed-Matter Physics & Materials Science Seminar

    "Spin-liquids in novel triangular and kagome rare-earth magnets"

    Presented by Martin Mourigal, Georgia Tech

    1:30 pm, Bldg. 734, ISB Conference Room 201 (upstairs)

    Friday, April 28, 2017, 1:30 pm

    Hosted by: '''Igor Zaliznyak'''

    Insulating magnets combining the effects of geometrical frustration with strong spin-orbit coupling offer a prime route to realize correlated quantum states with exotic ground-states and excitations. Spin-space anisotropy and bond-directional magnetic exchange interactions are naturally present in rare-earth oxides. One of the most celebrated consequence is the existence of classical and quantum "spin-ice" physics in rare-earth pyrochlores, materials in which magnetic ions occupy a three-dimensional network of corner-sharing tetrahedra. In this talk, I will present the discovery of distinct flavors of exotic magnetic matter in families of rare-earth oxides with two-dimensional kagome [1] and triangular [2] geometries. This experimental work relies on recent advances in materials synthesis and combines thermodynamic characterization with state-of-the-art neutron scattering experiments to unravel the classical or quantum nature of these newly discovered quasi-two-dimensional spin-liquids. [1] Emergent order in the kagome Ising magnet Dy3Mg2Sb3O14, J. A. M. Paddison, H. S. Ong, J. O. Hamp, P. Mukherjee, X. Bai, M. G. Tucker, N. P. Butch, C. Castelnovo, M. Mourigal, and S. E. Dutton, Nature Communications 7, 13842 (2016). [2] Continuous excitations of the triangular-lattice quantum spin liquid YbMgGaO4, J. A. M. Paddison, M. Daum, Z. L. Dun, G. Ehlers, Y. Liu, M. B. Stone, H. D. Zhou, and M. Mourigal, Nature Physics AOP (2016).

  4. MAY

    18

    Thursday

    Brookhaven Women In Science Lecture

    "Self-Organization and Understanding"

    Presented by Natika Newton, PhD, Nassau Community College

    4 pm, Hamilton Seminar Room, Bldg. 555

    Thursday, May 18, 2017, 4:00 pm

    This talk has three parts: 1. I discuss the phenomenon of understanding – our ordinary experience of understanding the objects and events in our environment. Normally we do not pay attention to the understanding process itself, but just to what is understood (e.g. I understand the ordinary things you say, but do not enquire how it is that I understand them); here we focus upon the process. I argue that understanding holds an important key to the nature of human cognition—our ability to think and reason. 2. Next I examine the process of self-organization – the process whereby a type of general order arises from local interactions between parts of an originally chaotic system. Self-organization is so-called because the order is not controlled by any agent external to the system. Many familiar phenomena are self-organized, from rush-hour traffic patterns to ant hills, as well as many organic processes within our bodies. 3. Finally, I attempt to show that understanding is a self-organizing process. In considering cognitive functions in the brain, I take a top-down rather than a bottom-up approach. A top-down approach starts with a general system, in this case our conscious awareness of understanding, and breaks it down into (sometimes unconscious) subsystems. I argue that the sort of understanding we are familiar with is possible only through the self-organized subsystems of our ordinary understanding of our situation and environment.