Zobrazeno 1 - 10
of 130
pro vyhledávání: '"Johnson, Allan S"'
Strong field terahertz pulses are increasingly used to excite and control quantum materials at the ultrafast timescale. They have found widespread application by enabling direct addressing of the superconducting gap or Josephson resonances and are es
Externí odkaz:
http://arxiv.org/abs/2403.04538
Autor:
Munoz, Gilberto A. de la Pena, Correa, Alfredo A., Yang, Shan, Delaire, Olivier, Huang, Yijing, Johnson, Allan S., Katayama, Tetsuo, Krapivin, Viktor, Pastor, Ernest, Reis, David A., Teitelbaum, Samuel, Vidas, Luciana, Wall, Simon, Trigo, Mariano
In the prevalent picture of ultrafast structural phase transitions, the atomic motion occurs in a slowly varying potential energy surface determined adiabatically by the fast electrons. However, this ignores non-conservative forces caused by electron
Externí odkaz:
http://arxiv.org/abs/2402.13133
Autor:
Sarkar, Arnab, Johnson, Allan S.
Condensed phase systems often exhibit a mixture of deterministic and stochastic dynamics at the nanoscale which are essential to understanding their function, but can be challenging to study directly using conventional imaging methods. Coherent X-ray
Externí odkaz:
http://arxiv.org/abs/2402.10585
Autor:
Brahms, Christian, Zhang, Lin, Shen, Xiao, Bhattacharya, Utso, Recasens, Maria, Osmond, Johann, Grass, Tobias, Chhajlany, Ravindra W., Hallman, Kent A., Haglund, Richard F., Pantelides, Sokrates T., Lewenstein, Maciej, Travers, John C., Johnson, Allan S.
The nature of the insulator-to-metal phase transition in vanadium dioxide (VO2) is one of the longest-standing problems in condensed-matter physics. Ultrafast spectroscopy has long promised to determine whether the transition is primarily driven by t
Externí odkaz:
http://arxiv.org/abs/2402.01266
Autor:
Zhang, Lin, Bhattacharya, Utso, Recasens, Maria, Grass, Tobias, Chhajlany, Ravindra W., Lewenstein, Maciej, Johnson, Allan S.
Nonequilibrium phase transitions driven by light pulses represent a rapidly developing field in condensed matter physics. As one of the archetypal strongly correlated materials, vanadium dioxide (VO2) undergoes a structural phase transition (SPT) fro
Externí odkaz:
http://arxiv.org/abs/2402.01247
Determination and correction of spectral phase from principal component analysis of coherent phonons
Publikováno v:
Optics Express 32, 3817 (2024)
Measuring the spectral phase of a pulse is key for performing wavelength resolved ultrafast measurements in the few femtosecond regime. However, accurate measurements in real experimental conditions can be challenging. We show that the reflectivity c
Externí odkaz:
http://arxiv.org/abs/2311.14853
Autor:
Johnson, Allan S., Pastor, Ernest, Batlle-Porro, Sergi, Benzidi, Hind, Katayama, Tetsuo, Muñoz, Gilberto A. de la Peña, Krapivin, Viktor, Kim, Sunam, López, Núria, Trigo, Mariano, Wall, Simon E.
Publikováno v:
Nature Physics (2024)
Ultrafast manipulation of vibrational coherence is an emergent route to control the structure of solids. However, this strategy can only induce long-range correlations and cannot modify atomic structure locally, which is required in many technologica
Externí odkaz:
http://arxiv.org/abs/2309.13275
Autor:
Ferté, Anthony, Austin, Dane, Johnson, Allan S., McGrath, Felicity, Malhado, João Pedro, Marangos, Jon P., Vacher, Morgane
Ultrashort pulses can excite or ionize molecules and populate coherent electronic wavepackets, inducing complex dynamics. In this work, we simulate the coupled electron-nuclear dynamics upon ionization to different electronic wavepackets of (deuterat
Externí odkaz:
http://arxiv.org/abs/2309.08269
Autor:
Johnson, Allan S., Pérez-Salinas, Daniel, Siddiqui, Khalid M., Kim, Sungwon, Choi, Sungwook, Volckaert, Klara, Majchrzak, Paulina E., Ulstrup, Søren, Agarwal, Naman, Hallman, Kent, Haglund Jr., Richard F., Günther, Christian M., Pfau, Bastian, Eisebitt, Stefan, Backes, Dirk, Maccherozzi, Francesco, Fitzpatrick, Ann, Dhesi, Sarnjeet, Gargiani, Pierluigi, Valvidares, Manuel, Artrith, Nongnuch, de Groot, Frank, Choi, Hyeongi, Jang, Dogeun, Katoch, Abhishek, Kwon, Soonnam, Park, Sang Han, Kim, Hyunjung, Wall, Simon E.
Publikováno v:
Nature Physics 2022
Using light to control transient phases in quantum materials is an emerging route to engineer new properties and functionality, with both thermal and non-thermal phases observed out of equilibrium. Transient phases are expected to be heterogeneous, e
Externí odkaz:
http://arxiv.org/abs/2202.08585
Autor:
Pastor, Ernest, Moreno-Mencía, David, Monti, Maurizio, Johnson, Allan S., Fleischmann, Nina, Wang, Cuixiang, Shi, Youguo, Liu, Xuerong, Mazzone, Daniel G., Dean, Mark P. M., Wall, Simon
Publikováno v:
Physical Review B 105, 064409 (2022)
In Mott insulators the evolution of antiferromagnetic order to superconducting or charge-density-wave-like states upon chemical doping underpins the control of quantum phases. Photo-doping can induce similar transitions on the ultrafast timescale, ho
Externí odkaz:
http://arxiv.org/abs/2104.04294