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Chini, Michael

Publications and source records attributed to Chini, Michael.

5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

DOE Support for the 8th International Conference on Attosecond Science (Final Technical Report)

The 8th International Conference on Attosecond Science and Technology (ATTO VIII) was held on the campus of the University of Central Florida in Orlando, FL from July 10-16, 2022. The main objectives of the conference were (i) to outline the state of the art of attosecond research; (ii) to jump-start national and international collaborations that had been hindered by the pandemic; (iii) to promote recruiting and training of postdocs and tenure-track candidates; and (iv) to consolidate the global and diverse identity of the attosecond community.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2022

Ultrafast relaxation of acoustic and optical phonons in a topological nodal-line semimetal ZrSiS

Recently, nodal line semimetals based on ZrSiS-family have garnered massive research interests contributing numerous experimental and theoretical works. Despite being the most studied nodal-line semimetal, a clear understanding of the transient state relaxation dynamics and the underlying mechanism in ZrSiS is lacking. Using time- and angle-resolved photoemission spectroscopy, we study the ultrafast relaxation dynamics in ZrSiS and reveal a unique relaxation in the bulk nodal-line state which is well-captured by a simple model based on optical and acoustic phonon cooling. Our model predicts linear decay processes for both optical and acoustic phonon relaxations with optical cooling dominant at higher temperatures. Our results reveal different decay mechanisms for the bulk and surface states and pave a way to understand the mechanism of conduction in this material.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2021

Effect of Dilute Magnetism in a Topological Insulator

Three-dimensional (3D) topological insulator (TI) has emerged as a unique state of quantum matter and generated enormous interests in condensed matter physics. The surfaces of a 3D TI consist of a massless Dirac cone, which is characterized by the Z 2 topological invariant. Introduction of magnetism on the surface of a TI is essential to realize the quantum anomalous Hall effect and other novel magneto-electric phenomena. Here, by using a combination of first-principles calculations, magneto-transport and angle-resolved photoemission spectroscopy (ARPES), we study the electronic properties of gadolinium (Gd)-doped Sb 2 Te 3 . Our study shows that Gd doped Sb 2 Te 3 is a spin-orbit-induced bulk band-gap material, whose surface is characterized by a single topological surface state. Our results provide a new platform to investigate the interactions between dilute magnetism and topology in magnetic doped topological materials.

36 MATERIALS SCIENCE↗