Pegeen Ryan

About

Pegeen Ryan is an Associate Professor of the Practice in the College of Communication at Boston University. She joined the college after working on the creative side of the advertising business for 30 years. Her career began as an art director, and she rose to the position of VP Creative Director at various Boston advertising agencies. She spent a significant portion of her career at Digitas, where she served as Creative Director for major brands such as P&G, The Home Depot, GM, and Gillette. Pegeen Ryan has won numerous awards, including Cannes, MITX, Echo, and Hatch. She teaches creative courses for both graduate and undergraduate students, sharing her extensive industry experience and expertise.

Research topics

• Optoelectronics
• Crystallography
• Metallurgy
• Materials science
• Chemistry
• Condensed matter physics
• Physics
• Quantum mechanics

Selected publications

• Controlling spin current polarization through non-collinear antiferromagnetism

  Nature Communications · 2020 · 197 citations

  The interconversion of charge and spin currents via spin-Hall effect is essential for spintronics. Energy-efficient and deterministic switching of magnetization can be achieved when spin polarizations of these spin currents are collinear with the magnetization. However, symmetry conditions generally restrict spin polarizations to be orthogonal to both the charge and spin flows. Spin polarizations can deviate from such direction in nonmagnetic materials only when the crystalline symmetry is reduc…

  DOI

• The Classical-to-Quantum Crossover in strain-induced ferroelectric transition in SrTiO$_3$ membranes

  ArXiv.org · 2025-02-04

  preprintOpen access

  Mechanical strain presents an effective control over symmetry-breaking phase transitions. In quantum paralelectric SrTiO3, strain can induce the ferroelectric transition via modification of local Ti potential landscape. However, brittle bulk materials can only withstand limited strain range (~0.1%). Taking advantage of nanoscopically-thin freestanding membranes, we demonstrated in-situ strain-induced reversible ferroelectric transition in a single freestanding SrTiO3 membranes. We measure the fe…

  PublisherOA PDFDOI

• Chiral Spin-Liquid-Like State in Pyrochlore Iridate Thin Films

  arXiv (Cornell University) · 2024-03-10

  preprintOpen access

  The pyrochlore iridates have become ideal platforms to unravel fascinating correlated and topolog?ical phenomena that stem from the intricate interplay among strong spin-orbit coupling, electronic correlations, lattice with geometric frustration, and itinerancy of the 5d electrons. The all-in-all?out antiferromagnetic state, commonly considered as the magnetic ground state, can be dramatically altered in reduced dimensionality, leading to exotic or hidden quantum states inaccessible in bulk. Her…

  PublisherOA PDFDOI

• Pulling order back from the brink of disorder: Observation of a nodal line spin liquid and fluctuation stabilized order in K$_2$IrCl$_6$

  arXiv (Cornell University) · 2024-07-24

  preprintOpen access

  Competing interactions in frustrated magnets can give rise to highly degenerate ground states from which correlated liquid-like states of matter often emerge. The scaling of this degeneracy influences the ultimate ground state, with extensive degeneracies potentially yielding quantum spin liquids, while sub-extensive or smaller degeneracies yield static orders. A longstanding problem is to understand how ordered states precipitate from this degenerate manifold and what echoes of the degeneracy s…

  PublisherOA PDFDOI

• Effect of disorder on the strain-tuned charge density wave multicriticality in Pd$_x$ErTe$_3$

  arXiv (Cornell University) · 2024-12-30

  preprintOpen access

  We explore, through a combination of x-ray diffraction and elastoresistivity measurements, the effect of disorder on the strain-tuned charge density wave and associated multicriticality in Pd$_x$ErTe$_3$ (x = 0, 0.01, 0.02 and 0.026). We focus particularly on the behavior near the strain-tuned bicritical point that occurs in pristine ErTe$_3$ (x=0). Our study reveals that while Pd intercalation somewhat broadens the signatures of the CDW phase transitions, the line of first-order transitions at…

  PublisherOA PDFDOI

Frequent coauthors

• Jong‐Woo Kim

  Weatherford College

  143 shared

• Jian Liu

  63 shared

• Yongseong Choi

  Argonne National Laboratory

  42 shared

• Jiun‐Haw Chu

  University of Washington

  42 shared

• Lin Hao

  39 shared

• Junyi Yang

  37 shared

• D. Meyers

  Oklahoma State University Oklahoma City

  35 shared

• Darrell G. Schlom

  Leibniz Institute for Crystal Growth

  34 shared

Awards & honors

• Cannes Award
• MITX Award
• Echo Award
• Hatch Award

Similar researchers at Boston University

• Amy Gellerh-75
• Justin Josephh-56
• Susanna S. Leeh-51