Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Real-Time Observation of a Coherent Lattice Transformation into a High-Symmetry Phase
Δημιουργός/Συγγραφέας:	Teitelbaum S.W. Shin T. Wolfson J.W. Cheng Y.-H. Porter I.J. [EL] Κάνδυλα, Μαρία[EN] Kandyla, Maria Nelson K.A.
Εκδότης:	American Physical Society
Ημερομηνία:	2018
Γλώσσα:	Αγγλικά
ISSN:	2160-3308
DOI:	10.1103/PhysRevX.8.031081
Περίληψη:	Excursions far from their equilibrium structures can bring crystalline solids through collective transformations including transitions into new phases that may be transient or long-lived. The direct spectroscopic observation of far-from-equilibrium rearrangements provides fundamental mechanistic insight into chemical and structural transformations and a potential route to practical applications, including ultrafast optical control over material structure and properties. However, in many cases, photoinduced transitions are irreversible or only slowly reversible, or the light fluence required exceeds material damage thresholds. This requirement precludes conventional ultrafast spectroscopy, in which optical excitation and probe pulses irradiate the sample many times, each measurement providing information about the sample response at just one probe delay time following excitation, with each measurement at a high repetition rate and with the sample fully recovering its initial state in between measurements. Using a single-shot, real-time measurement method, we are able to observe the photoinduced phase transition from the semimetallic, low-symmetry phase of crystalline bismuth into a high-symmetry phase whose existence at high electronic excitation densities is predicted based on earlier measurements at moderate excitation densities below the damage threshold. Our observations indicate that coherent lattice vibrational motion launched upon photoexcitation with an incident fluence above 10 mJ/cm2 in bulk bismuth brings the lattice structure directly into the high-symmetry configuration for several picoseconds, after which carrier relaxation and diffusion restore the equilibrium lattice configuration.
Τίτλος πηγής δημοσίευσης:	Physical Review X
Τόμος/Κεφάλαιο:	8
Τεύχος:	3
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry [EL] Φασματοσκοπία[EN] Spectroscopy
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© 2018 authors. Published by the American Physical Society.
Όροι και προϋποθέσεις δικαιωμάτων:	All Open Access, Gold, Green
Σημειώσεις:	National Science Foundation, NSF: CHE-1111557, ECS-0335765; National Research Foundation of Korea, NRF: NRF-2016R1C1B2010444; Office of Naval Research, ONR: N00014-12-1-0530, N00014-16-1-2090 This work was also supported by Office of Naval Research Grants No. N00014-12-1-0530 and No. N00014-16-1-2090 and the National Science Foundation Grant No. CHE-1111557. This work was performed in part at the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Infrastructure Network (NNIN), which is supported by the National Science Foundation under Grant No. ECS-0335765. Center for Nanoscale Systems is part of Harvard University. T. S. acknowledges the support from the National Research Foundation of Korea (NRF-2016R1C1B2010444).
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο