March 14, 2018 - Work done by the Krivorotov group, in collaboration with the M. Wu group, is the subject of a research highlight in the latest issue of Frontiers in Energy Research, a quarterly newsletter published by the DOE Office of Science. The paper described the creation of a device that used heat to drive spin currents, opening the door for highly efficient spintronic devices that utilize the waste heat given off by conventional electronics.
Spin-phonon coupling in antiferromagnetic nickel oxide
January 16, 2018 - A research team led by SHINES PIs Prof. Balandin, Prof. Shi and Prof. Lake at UC Riverside has determined the spin-phonon coupling coefficients of the antiferromagnetic material (NiO) utilizing ultraviolet (λ=325 nm) Raman spectroscopy. Their results established that the spins of Ni atoms interact more strongly with longitudinal optical phonons (compared to transverse optical phonons) and produce opposite effects on the phonon energies. The paper was published in Appl. Phys. Lett. and highlighted by UCR Today.
Enhanced interlayer carrier multiplication in 2D semiconductor heterostructures
October 9, 2017 - The Gabor group, in collaboration with the Lake group, has shown that 2D transition metal dichalcogenide heterostructures can be used to efficiently multiply photocurrent at the nanoscale. The work was published in Nature Nanotechnology. and highlighted by UCR Today.
Harnessing Quantum Vortices
A collaborative project by the groups of Elaine Li and Kang Wang has been profiled in Frontiers in Energy Research, the quarterly newsletter published by the DOE Office of Science. The project is notable for demonstrating the creation and control of skyrmion dimensions at room-temperature.
Chiral Majorana fermion modes in a quantum anomalous Hall insulator–superconductor structure
Kang L. Wang group has published a paper in Science on Majoran fermion modes. They report transport measurements that suggest the existence of one-dimensional chiral Majorana fermion modes in the hybrid system of a quantum anomalous Hall insulator thin film coupled with a superconductor. As the external magnetic field is swept, half-integer quantized conductance plateaus are observed at the locations of magnetization reversals, giving a distinct signature of the Majorana fermion modes.The work is highlighted in UCLA news.
Above 400-K robust perpendicular ferromagnetic phase in a topological insulator
The Shi group has made topological insulator (TI) surfaces magnetic from room temperature to more than 400 Kelvin. The Curie temperature (Tc) is enhanced by exchange coupling TIs to Tm3Fe5O12, a high-Tc magnetic insulator with perpendicular magnetic anisotropy. Distinct squared anomalous Hall hysteresis loops at 400 K reveal that the TI surface states acquire robust ferromagnetism. The paper was published in SCIENCE ADVANCES and highlighted by UCR Today.
SHINES Workshop January 2017
SHINES will hold a workshop on spin and heat from January 12-13th, 2017 at the UCR Palm Desert Center.
Workshop program is here http://efrcshines.ucr.edu/files/1.pdf.
Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires
Research team led by SHINES PI Prof. Balandin at UC Riverside discover new method to dissipate heat in electronic devices by modulating the flow of phonons (elemental excitations) through semiconductor nanowires. They report results of Brillouin—Mandelstam light scattering spectroscopy, which reveal multiple (up to ten) confined acoustic phonon polarization branches in GaAs nanowires with a diameter as large as 128 nm, at a length scale that exceeds the grey phonon mean-free path in this material by almost an order-of-magnitude. The dispersion modification and energy scaling with diameter in individual nanowires are in excellent agreement with theory. The phonon confinement effects result in a decrease in the phonon group velocity along the nanowire axis and changes in the phonon density of states. The obtained results can lead to more efficient nanoscale control of acoustic phonons, with benefits for nanoelectronic, thermoelectric and spintronic devices.
This work is published in Nature Communication.
Oct.31 to Nov.4 2016
SHINES talks for symposium titled “Topological Insulator/ Ferromagnet Heterostrctures for spintronics” at MMM Conference 2016.
Three SHINES PIs; Prof. Jing Shi, Prof. Kang L. Wang and Mingzhong Wu gave invited talks for the symposium titled “Topological Insulator/ Ferromagnet Heterostrctures for spintronics” at MMM 2016 held in New Orleans-Louisiana.
Prof. Shi’s talk is “Enhanced spin Seebeck effect in topological insulator/ magnetic insulator heterostructures”
Prof. Wang’s talk is “Topological Insulator/Ferromagnet Heterostructures for Spintronics”
Prof. Wu’s talk is “Photo-Spin-Voltaic Effect”
SHINES Research Highlighted by the US Department of Energy
In May, the newsletter of the DOE Office of Science described recent results obtained by the Balandin Group showing acoustic phonon confinement effects in nanoporous arrays. Understanding changes in the acoustic phonon spectrum induced by spatial confinement is important for the fine-tuning of heat propagation in nanometer scale structures and electronic devices. Investigation of the acoustic phonons was made possible by development of the Brillouin-Mandelstam spectroscopy tool at UC Riverside. Fariborz Kargar (pictured to the left) – Research Assistant and PhD Candidate in Balandin group – was the first author of the paper published in Applied Physics Letters.
Congressman Mark Takano visits Device Discovery Lab
On March 11th, US Congressman Mark Takano (41st district) visited Professor Khitun's Device Discovery Lab and had a thirty minute discussion about the ongoing research on magnonic holographic imaging of magnetic nanostructures. This work is supported by the SHINES center and director Professor Jing Shi.
Shi Group Research Profiled by UCR Today
A team of researchers, led by Jing Shi's group at UC Riverside, have demonstrated for the first time the transmission of electrical signals through insulators in a sandwich-like structure, a development that could help create more energy efficient electronic devices.
Dr. Elaine Li's research on ultrafast processes in atomically thin materials has been profiled by the UT Austin College of Natural Sciences. In October 2015, Dr. Li was elected to the American Physical Society.
Dr. Alexander Balandin, UC Presidential Chair Professor of Electrical and Computer Engineering is among the five UC Riverside professors included in the Most Influential Scientists list published by the Thomson Reuters. The Thomson Reuters Highly Cited Researchers list is published annually based on the number of citations in several categories. Dr. Balandin was selected in the Physics category.
Professor Jing Shi has been spotlighted in UCR's "Living the Promise" series focusing on breakthrough research. Professor Shi's lab focuses on fundamental problems associated with how to generate, conserve and save energy. Their focus is on spin and heat, specifically in trying to leverage the spin degree of freedom in electrons to convert other forms of energy into electricity, such as heat, more efficiently.
David Ellsworth of Mingzhong Wu's lab at CSU was a finalist for the Best Student Presentation Award at the 13th Joint MMM-Intermag Conference.
David Ellsworth of Mingzhong Wu's lab at CSU won the Best Poster Award at the 2015 Front Range Advanced Magnetics Symposium.
Professor Chia-Ling Chien has been awarded the 2015 IUPAP Magnetism Award and Néel Medal for pioneering discoveries in magnetic materials and nanostructures.
- The 11th International Nanotechnology Conference on Communication and Cooperation
- May 11-13, 2015 / Hilton Fukuoka Sea Hawk, Fukuoka, Japan
- Graduate Student’s Chi Tang and Aleksey Volodchenkov from UC Riverside, have been invited to present a poster and represent SHINES EFRC at this year’s conference.