1
|
Abel JJ, Wiesner F, Nathanael J, Reinhard J, Wünsche M, Schmidl G, Gawlik A, Hübner U, Plentz J, Rödel C, Paulus GG, Fuchs S. Absolute EUV reflectivity measurements using a broadband high-harmonic source and an in situ single exposure reference scheme. OPTICS EXPRESS 2022; 30:35671-35683. [PMID: 36258513 DOI: 10.1364/oe.463216] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/02/2022] [Indexed: 06/16/2023]
Abstract
We present a tabletop setup for extreme ultraviolet (EUV) reflection spectroscopy in the spectral range from 40 to 100 eV by using high-harmonic radiation. The simultaneous measurements of reference and sample spectra with high energy resolution provide precise and robust absolute reflectivity measurements, even when operating with spectrally fluctuating EUV sources. The stability and sensitivity of EUV reflectivity measurements are crucial factors for many applications in attosecond science, EUV spectroscopy, and nano-scale tomography. We show that the accuracy and stability of our in situ referencing scheme are almost one order of magnitude better in comparison to subsequent reference measurements. We demonstrate the performance of the setup by reflective near-edge x-ray absorption fine structure measurements of the aluminum L2/3 absorption edge in α-Al2O3 and compare the results to synchrotron measurements.
Collapse
|
2
|
Borrego-Varillas R, Lucchini M, Nisoli M. Attosecond spectroscopy for the investigation of ultrafast dynamics in atomic, molecular and solid-state physics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:066401. [PMID: 35294930 DOI: 10.1088/1361-6633/ac5e7f] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 03/16/2022] [Indexed: 06/14/2023]
Abstract
Since the first demonstration of the generation of attosecond pulses (1 as = 10-18s) in the extreme-ultraviolet spectral region, several measurement techniques have been introduced, at the beginning for the temporal characterization of the pulses, and immediately after for the investigation of electronic and nuclear ultrafast dynamics in atoms, molecules and solids with unprecedented temporal resolution. The attosecond spectroscopic tools established in the last two decades, together with the development of sophisticated theoretical methods for the interpretation of the experimental outcomes, allowed to unravel and investigate physical processes never observed before, such as the delay in photoemission from atoms and solids, the motion of electrons in molecules after prompt ionization which precede any notable nuclear motion, the temporal evolution of the tunneling process in dielectrics, and many others. This review focused on applications of attosecond techniques to the investigation of ultrafast processes in atoms, molecules and solids. Thanks to the introduction and ongoing developments of new spectroscopic techniques, the attosecond science is rapidly moving towards the investigation, understanding and control of coupled electron-nuclear dynamics in increasingly complex systems, with ever more accurate and complete investigation techniques. Here we will review the most common techniques presenting the latest results in atoms, molecules and solids.
Collapse
Affiliation(s)
- Rocío Borrego-Varillas
- Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Matteo Lucchini
- Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Department of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Mauro Nisoli
- Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche (CNR), Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Department of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| |
Collapse
|
3
|
Dolso GL, Moio B, Inzani G, Di Palo N, Sato SA, Borrego-Varillas R, Nisoli M, Lucchini M. Reconstruction of ultrafast exciton dynamics with a phase-retrieval algorithm. OPTICS EXPRESS 2022; 30:12248-12267. [PMID: 35472864 DOI: 10.1364/oe.451759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
The first step to gain optical control over the ultrafast processes initiated by light in solids is a correct identification of the physical mechanisms at play. Among them, exciton formation has been identified as a crucial phenomenon which deeply affects the electro-optical properties of most semiconductors and insulators of technological interest. While recent experiments based on attosecond spectroscopy techniques have demonstrated the possibility to observe the early-stage exciton dynamics, the description of the underlying exciton properties remains non-trivial. In this work we propose a new method called extended Ptychographic Iterative engine for eXcitons (ePIX), capable of reconstructing the main physical properties which determine the evolution of the quasi-particle with no prior knowledge of the exact relaxation dynamics or the pump temporal characteristics. By demonstrating its accuracy even when the exciton dynamics is comparable to the pump pulse duration, ePIX is established as a powerful approach to widen our knowledge of solid-state physics.
Collapse
|
4
|
Lucchini M, Sato SA, Lucarelli GD, Moio B, Inzani G, Borrego-Varillas R, Frassetto F, Poletto L, Hübener H, De Giovannini U, Rubio A, Nisoli M. Unravelling the intertwined atomic and bulk nature of localised excitons by attosecond spectroscopy. Nat Commun 2021; 12:1021. [PMID: 33589638 PMCID: PMC7884782 DOI: 10.1038/s41467-021-21345-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/25/2021] [Indexed: 11/09/2022] Open
Abstract
The electro-optical properties of most semiconductors and insulators of technological interest are dominated by the presence of electron-hole quasi-particles, called excitons. The manipulation of excitons in dielectrics has recently received great attention, with possible applications in different fields including optoelectronics and photonics. Here, we apply attosecond transient reflection spectroscopy in a sequential two-foci geometry and observe sub-femtosecond dynamics of a core-level exciton in bulk MgF2 single crystals. Furthermore, we access absolute phase delays, which allow for an unambiguous comparison with theoretical calculations. Our results show that excitons surprisingly exhibit a dual atomic- and solid-like character, which manifests itself on different time scales. While the former is responsible for a femtosecond optical Stark effect, the latter dominates the attosecond excitonic response. Further theoretical investigation reveals a link with the exciton sub-femtosecond nanometric motion and allows us to envision a new route to control exciton dynamics in the close-to-petahertz regime.
Collapse
Affiliation(s)
- Matteo Lucchini
- Department of Physics, Politecnico di Milano, 20133, Milano, Italy. .,Institute for Photonics and Nanotechnologies, IFN-CNR, 20133, Milano, Italy.
| | - Shunsuke A Sato
- Center for Computational Sciences, University of Tsukuba, Tsukuba, 305-8577, Japan.,Max Planck Institute for the Structure and Dynamics of Matter, 22761, Hamburg, Germany
| | - Giacinto D Lucarelli
- Department of Physics, Politecnico di Milano, 20133, Milano, Italy.,Institute for Photonics and Nanotechnologies, IFN-CNR, 20133, Milano, Italy
| | - Bruno Moio
- Department of Physics, Politecnico di Milano, 20133, Milano, Italy
| | - Giacomo Inzani
- Department of Physics, Politecnico di Milano, 20133, Milano, Italy
| | | | - Fabio Frassetto
- Institute for Photonics and Nanotechnologies, IFN-CNR, 35131, Padova, Italy
| | - Luca Poletto
- Institute for Photonics and Nanotechnologies, IFN-CNR, 35131, Padova, Italy
| | - Hannes Hübener
- Max Planck Institute for the Structure and Dynamics of Matter, 22761, Hamburg, Germany
| | - Umberto De Giovannini
- Max Planck Institute for the Structure and Dynamics of Matter, 22761, Hamburg, Germany.,Nano-Bio Spectroscopy Group, Universidad del País Vasco, 20018, San Sebastian, Spain
| | - Angel Rubio
- Max Planck Institute for the Structure and Dynamics of Matter, 22761, Hamburg, Germany.,Nano-Bio Spectroscopy Group, Universidad del País Vasco, 20018, San Sebastian, Spain
| | - Mauro Nisoli
- Department of Physics, Politecnico di Milano, 20133, Milano, Italy.,Institute for Photonics and Nanotechnologies, IFN-CNR, 20133, Milano, Italy
| |
Collapse
|
5
|
Dolso GL, Moio B, Inzani G, Di Palo N, Borrego-Varillas R, Nisoli M, Lucchini M. Ultrafast exciton dynamics reconstruction with a ptychographic approach. EPJ WEB OF CONFERENCES 2021. [DOI: 10.1051/epjconf/202125513005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Excitons characterize the ultrafast response of many materials of technological interest. While the development of attosecond science has unlocked the possibility of performing experiments with a suitable timeresolution, the access to the exciton properties remains a non-trivial step. We propose therefore a novel approach to disclose the physical properties behind the ultrafast exciton dynamics based on a phase-retrieval method.
Collapse
|