Femtosecond Structural Dynamics in VO2 during an Ultrafast Solid-Solid Phase Transition.
نویسندگان
چکیده
Femtosecond x-ray and visible pulses were used to probe structural and electronic dynamics during an optically driven, solid-solid phase transition in VO(2). For high interband electronic excitation (approximately 5 x 10(21) cm(-3)), a subpicosecond transformation into the high-T, rutile phase of the material is observed, simultaneous with an insulator-to-metal transition. The fast time scale observed suggests that, in this regime, the structural transition may not be thermally initiated.
منابع مشابه
Dynamics of Ultrafast Phase Changes in Amorphous GeSb Films
The existence of nonthermal, ultrafast phase transitions after strong femtosecond laser excitation has been demonstrated in several materials such as silicon [1–3], gallium arsenide [3–6], indium antimonide [7], and carbon [8]. It is accepted that such transitions are induced by a softening of the lattice structure due to the generation of a very high density electron-hole plasma, as first prop...
متن کاملAn atomic-level view of melting using femtosecond electron diffraction.
We used 600-femtosecond electron pulses to study the structural evolution of aluminum as it underwent an ultrafast laser-induced solid-liquid phase transition. Real-time observations showed the loss of long-range order that was present in the crystalline phase and the emergence of the liquid structure where only short-range atomic correlations were present; this transition occurred in 3.5 picos...
متن کاملInstantaneous band gap collapse in photoexcited monoclinic VO2 due to photocarrier doping.
Using femtosecond time-resolved photoelectron spectroscopy we demonstrate that photoexcitation transforms monoclinic VO2 quasi-instantaneously into a metal. Thereby, we exclude an 80 fs structural bottleneck for the photoinduced electronic phase transition of VO2. First-principles many-body perturbation theory calculations reveal a high sensitivity of the VO2 band gap to variations of the dynam...
متن کاملFemtosecond x-ray measurement of ultrafast melting and large acoustic transients.
Time-resolved x-ray diffraction with ultrashort ( approximately 300 fs), multi-keV x-ray pulses has been used to study the femtosecond laser-induced solid-to-liquid phase transition in a thin crystalline layer of germanium. Nonthermal melting is observed to take place within 300-500 fs. Following ultrafast melting we observe strong acoustic perturbations evolving on a picosecond time scale.
متن کاملMesoscopic structural phase progression in photo-excited VO2 revealed by time-resolved x-ray diffraction microscopy
Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase separated regions. The ability to simultaneously track the spatial and te...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 87 23 شماره
صفحات -
تاریخ انتشار 2001