Assistant Professor Smallwood publishes findings in ‘Science’

Christopher Smallwood

Christopher Smallwood

San Jose State University Assistant Professor Christopher Smallwood’s latest research appears in Science on Dec. 14. A member of the College of Science Department of Physics and Astronomy, he worked with colleagues at the University of California, Berkeley and Lawrence Berkeley National Laboratory to study the electronic and magnetic properties of the cuprate high-temperature superconductor bismuth strontium calcium copper oxide (Bi2212) using the novel spectroscopic technique of spin- and angle-resolved photoemission spectroscopy (SARPES). Their article is entitled “Revealing hidden spin-momentum locking in a high-temperature cuprate superconductor.”

SARPES is a spin-sensitive variation of the more commonly implemented technique of angle-resolved photoemission spectroscopy (ARPES), which itself is an electron spectroscopy technique based on the photoelectric effect that makes it possible to observe the relationship between the energy and momentum of a material’s electrons [see panel (A) below]. As such, the technique enjoys the distinction of being among the most important modern experimental probes of material properties in existence, providing information on the role of a material as an electrical conductor or insulator, on the presence or absence of topological order, and (in this case) on the propensity of the material to exhibit superconductivity and magnetic order.

Their work is important as superconductivity is an exotic state of matter in which a material’s electrical resistivity drops perfectly to zero at low temperature. Due to the superior way in which electricity can flow in this state, materials exhibiting superconductivity have found their way into a number of applications including nuclear magnetic resonance (MRI) and the technology enabling high-energy particle accelerators. The phenomenon is also of great intrinsic scientific interest as the onset of superconductivity at anomalously high temperatures in copper-oxide-based and iron-based materials remains an unsolved question in condensed matter physics.

Experiments were performed by graduate students Kenneth Gotlieb and Chiu-Yun Lin under the leadership of Professor Alessandra Lanzara at Lawrence Berkeley National Laboratory and UC Berkeley. With the spin resolution enabled by SARPES, the study reveals and characterizes magnetic properties of Bi2212 that have gone unnoticed in previous studies [see panel (B), where the blue shading indicates spin polarization; and panel (C) which depicts a theoretically proposed spin texture], and which run counter to some of the prevailing theoretical ideas about the material’s electrical properties. In particular, the findings pose new challenges for the Hubbard model and its variants where the spin-orbit interaction is mostly neglected, and they raise the intriguing question of how cuprate superconductivity emerges in the presence of a nontrivial spin texture, as superconductivity and magnetism are normally considered to be competing forms of long-range electronic order.

‘One Carbon Footprint At A Time’ Airs on KQED

San Jose State University Emeritus Professor Bob Gliner’s latest documentary will premiere on KQED on Jan. 2 at 11:30 p.m. and repeat on Jan. 3, at 5:30 a.m.

The former Sociology professor is a prolific filmmaker who has traveled the world to produced documentaries focused on social issues and social change. He combines his interest in education and climate change in his latest half-hour documentary, “One Carbon Footprint At a Time.” The film highlights how education can inspire everyday actions that play a critical and potentially transformative role in affecting climate change. The film explores a unique interdisciplinary Global Climate course at SJSU as well as classes at two San Jose area middle schools to see how the curriculum influences students to make changes in their daily lives.

The documentary features SJSU students, alumni and two faculty members, Eugene Cordero, from Meteorology and Climate Science, and Anne Marie Todd, from Communications Studies.

Gliner has received more than 16 awards for his films and was named as San Jose State’s 2002 President’s Scholar. For more information on Gliner’s latest documentary as well as other work, visit his website. For updates on the SJSU alumni featured in the film, visit the program’s website.

Moss Landing Professors Discuss ‘Tsunami Fish’ on CNN

San Jose State University’s Moss Landing Marine Laboratories (MLML) experts have a theory about how one fish swimming in the waters of the Monterey Bay ended up far from its natural habitat along the shores of Japan. A black-and-white striped fish known as the barred knifejaw, divers interviewed by CNN reporters described it as distinctive from the native fish in the cold and murky waters of the Bay.

Jonathan Geller, a professor and researcher based at SJSU’s MLML, told CNN on Dec. 13 that the fish likely landed in California as an after effect of the 2011 tsunami. Geller co-authored an article in Science that notes 289 living Japanese coastal species documented along the shores of Hawaii and North America following the tsunami in 2011.

“These currents circle around and around and then just depending on local conditions the water may move on shore,” Geller said. “This fish stands out because it looks quite alien in our water and it’s definitely a species we haven’t seen here before this event,” Geller told CNN, adding that many of the other species found looked like they belong.

Colleague and MLML researcher Rick Starr said the fish is unlikely to become invasive as fish from warmer areas can survive in cold water, but may not be able to reproduce.

“People have seen multiple fish, it’s not just one, but they’re all the same size indicating that they’re not offspring,” Starr said. “We’re not seeing multiple different size classes, so the best guess right now is that these fish are all older fish that haven’t reproduced.

Physics Professor Khatami Publishes Latest Groundbreaking Research in ‘Science’

Ehsan Khatami is one of two San Jose State University faculty members selected as an Early Career Investigator Award winner in 2017-18. (Photo: James Tensuan, '15 Journalism)

Ehsan Khatami is one of two San Jose State University faculty members selected as an Early Career Investigator Award winner in 2017-18. (Photo: James Tensuan, ’15 Journalism)

San Jose State University Associate Professor of Physics and Astronomy Ehsan Khatami in collaboration with a group of professors from MIT and the MIT-Harvard Center for Ultracold Atoms published today in the journal Science their latest experimental discovery about conduction in a tiny system of atoms in a vacuum.

Khatami, who was granted early tenure and promotion to associate professor this year, received a funding from the National Science Foundation with colleague Sen Chiao, of the Meteorology Department to build the first high-performance computing cluster on campus. The equipment has proven essential to his research as well as the work of students and faculty in other disciplines that require big data analysis.

In his most recent article, Khatami and his colleagues discuss an experiment that is impossible to perform using real materials. They were able to focus on the movement of atoms’ intrinsic magnetic field, or “spin,” across a few microns without disturbing their charge arrangement (charge is another intrinsic property of atoms) as the first of its kind with a quantum system. The results shed light on the mostly unexplored spin transport property of models condensed matter scientists use to describe the unusual behavior of solids at very low temperatures.

Atoms are like small magnets, so applying a magnetic force pushes them around, here to the left (top left). Since these atoms repel each other, they cannot move if there are no empty sites (top middle). But the atomic “magnetic needles” are still free to move, with stronger magnets (red) diffusing to the left in the image, and weaker magnets (blue) having to make room and move to the right (bottom row). This so-called spin transport is resolved atom by atom in the cold atom quantum emulator.

Atoms are like small magnets, so applying a magnetic force pushes them around, here to the left (top left). Since these atoms repel each other, they cannot move if there are no empty sites (top middle). But the atomic “magnetic needles” are still free to move, with stronger magnets (red) diffusing to the left in the image, and weaker magnets (blue) having to make room and move to the right (bottom row). This so-called spin transport is resolved atom by atom in the cold atom quantum emulator.

Khatami’s research aims to help scientists understand how superconductivity works—a finding that could potentially pave the way for a room-temperature superconductor, which would improve transportation and data storage and make homes more energy efficient by creating materials that allow better use of electricity. That is, as electricity goes through a device such as a phone or laptop, none of the electronic components would heat up. Superconductivity is the property of zero electrical resistance in some substances at very low temperatures (<-135 degrees Celsius).

The experiment was carried out using 400 atoms cooled down to just a hair above absolute zero temperature (<-273 degrees Celsius). The atoms were manipulated to be two different types and to act as if they were electrons in a solid with two species of spin. The atoms were then trapped in a square box to see how they would respond when magnetic fields keeping one species on the left side and one species on the right side of the box were turned off. Scientists watched the process by using an electron gas microscope to measure the speed at which mixing takes place and deduce the “spin” current.

Khatami compares the box of atoms to a shallow pool of water – if there was a divider in the middle with clear water on one side and water dyed black on the other side when the divider is suddenly removed the water would mix together and turn gray. The two shades of water would be similar to the two spin species in the quantum experiment, with the behavior of the atoms governed by quantum mechanics.

To support the experiment, Khatami used more than 300,000 CPU hours on SJSU’s Spartan High-Performance Computer to solve the underlying theoretical model that was emulated in the experiment to support experimental observations.

“As exciting as these findings have been, there are still so many unanswered questions we can explore using similar setups,” he said. “For example, the dependence of spin transport on the temperature or the concentration of atoms in the box can be studied.”

Khatami received the SJSU 2017-18 Early Career Investigator Award and has offered insights into his research on the web series Physics Girl. He was featured in the Fall/Winter 2018 edition of Washington Square alumni magazine.

Faculty Promotion: Nicholas Taylor

Nick Taylor

Nick Taylor

Nicholas Taylor

Promotion to Professor

Years at SJSU: 11

Department: English and Comparative Literature

RSCA focus: Creative Writing

English and Comparative Literature Professor Nicholas Taylor is a scholar of Steinbeck who serves as the director of SJSU’s Martha Heasley Cox Center for Steinbeck Studies. In this role, he coordinates the annual John Steinbeck Award, manages a Fellows program and coordinates other events that promote literature. He also served as a Fulbright-Nehru Visiting Lecturer in Hyderabad, India in 2011.

But when asked about his research, scholarship and creative activities, he first acknowledges his creative writing projects. He has published essays, short stories and is especially proud of a series of detective novels penned under his pseudonym T.T. Monday.

As a member of the University Library Board and the College of Humanities and the Arts RTP committee, he says his experiences with students have been a highlight of his nearly dozen years working at SJSU.

He appreciates the opportunity to connect with students, and recalls one student who came to SJSU as a transfer student who struggled with writing. Taylor worked with him for several years. The former student and SJSU alumnus now teaches high school English and has published a short story.

“Anyone interested in a career in the arts must learn, first of all, to be resilient,” he said. “The writing life is full of criticism and rejection. My advice, if you feel the calling, is to persevere and take pride in your work regardless of its reception.”

Note: Congratulations to the 43 faculty members who received tenure and/or promotion for 2018-19. We have invited each faculty member to participate in a series of posts profiling their teaching, service, and research, scholarship and creativity activities. Those faculty who opted to participate will be featured throughout the fall semester on the Academic Spotlight blog and the digital sign in the Administration Building lobby.