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Li S, Sharma A, Márton Z, Nugraha PS, Lombosi C, Ollmann Z, Márton I, Dombi P, Hebling J, Fülöp JA. Subcycle surface electron emission driven by strong-field terahertz waveforms. Nat Commun 2023; 14:6596. [PMID: 37852982 PMCID: PMC10584819 DOI: 10.1038/s41467-023-42316-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 10/06/2023] [Indexed: 10/20/2023] Open
Abstract
The advent of intense terahertz (THz) sources opened a new era when the demonstration of the acceleration and manipulation of free electrons by THz pulses became within reach. THz-field-driven electron emission was predicted to be confined to a single burst due to the single-cycle waveform. Here we demonstrate the confinement of single-cycle THz-waveform-driven electron emission to one of the two half cycles from a solid surface emitter. Either the leading or the trailing half cycle was active, controlled by reversing the field polarity. THz-driven single-burst surface electron emission sources, which do not rely on field-enhancement structures, will impact the development of THz-powered electron acceleration and manipulation devices, all-THz compact electron sources, THz waveguides and telecommunication, THz-field-based measurement techniques and solid-state devices.
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Affiliation(s)
- Shaoxian Li
- Szentágothai Research Centre, University of Pécs, 7624, Pécs, Hungary
- Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering, and the Key Laboratory of Optoelectronics Information and Technology, Ministry of Education, Tianjin University, 300072, Tianjin, China
| | - Ashutosh Sharma
- ELI-ALPS Research Institute, ELI-HU Non-Profit Ltd., 6728, Szeged, Hungary
| | - Zsuzsanna Márton
- ELI-ALPS Research Institute, ELI-HU Non-Profit Ltd., 6728, Szeged, Hungary
- Institute of Physics, University of Pécs, 7624, Pécs, Hungary
| | - Priyo S Nugraha
- Szentágothai Research Centre, University of Pécs, 7624, Pécs, Hungary
- HUN-REN-PTE High-Field Terahertz Research Group, 7624, Pécs, Hungary
| | - Csaba Lombosi
- Szentágothai Research Centre, University of Pécs, 7624, Pécs, Hungary
| | - Zoltán Ollmann
- Szentágothai Research Centre, University of Pécs, 7624, Pécs, Hungary
- Institute of Physics, University of Pécs, 7624, Pécs, Hungary
| | - István Márton
- Wigner Research Centre for Physics, 1121, Budapest, Hungary
- Institute for Nuclear Research (Atomki), 4001, Debrecen, Hungary
| | - Péter Dombi
- ELI-ALPS Research Institute, ELI-HU Non-Profit Ltd., 6728, Szeged, Hungary
- Wigner Research Centre for Physics, 1121, Budapest, Hungary
| | - János Hebling
- Szentágothai Research Centre, University of Pécs, 7624, Pécs, Hungary
- Institute of Physics, University of Pécs, 7624, Pécs, Hungary
- HUN-REN-PTE High-Field Terahertz Research Group, 7624, Pécs, Hungary
| | - József A Fülöp
- Szentágothai Research Centre, University of Pécs, 7624, Pécs, Hungary.
- ELI-ALPS Research Institute, ELI-HU Non-Profit Ltd., 6728, Szeged, Hungary.
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Brennecke S, Ranke M, Dimitriou A, Walther S, Prandolini MJ, Lein M, Frühling U. Control of Electron Wave Packets Close to the Continuum Threshold Using Near-Single-Cycle THz Waveforms. PHYSICAL REVIEW LETTERS 2022; 129:213202. [PMID: 36461977 DOI: 10.1103/physrevlett.129.213202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
The control of low-energy electrons by carrier-envelope-phase-stable near-single-cycle THz pulses is demonstrated. A femtosecond laser pulse is used to create a temporally localized wave packet through multiphoton absorption at a well defined phase of a synchronized THz field. By recording the photoelectron momentum distributions as a function of the time delay, we observe signatures of various regimes of dynamics, ranging from recollision-free acceleration to coherent electron-ion scattering induced by the THz field. The measurements are confirmed by three-dimensional time-dependent Schrödinger equation simulations. A classical trajectory model allows us to identify scattering phenomena analogous to strong-field photoelectron holography and high-order above-threshold ionization.
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Affiliation(s)
- Simon Brennecke
- Leibniz Universität Hannover, Institut für Theoretische Physik, Appelstraße 2, 30167 Hannover, Germany
| | - Martin Ranke
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Anastasios Dimitriou
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761 Hamburg, Germany
- Institute of Nanoscience and Nanotechnology, NSR Demokritos, 15341 Agia Paraskevi, Athens, Greece
| | - Sophie Walther
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Mark J Prandolini
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Manfred Lein
- Leibniz Universität Hannover, Institut für Theoretische Physik, Appelstraße 2, 30167 Hannover, Germany
| | - Ulrike Frühling
- Institut für Experimentalphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging (CUI), Luruper Chaussee 149, 22761 Hamburg, Germany
- Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
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Taoutioui A, Agueny H. Femtosecond Single Cycle Pulses Enhanced the Efficiency of High Order Harmonic Generation. MICROMACHINES 2021; 12:mi12060610. [PMID: 34073368 PMCID: PMC8227859 DOI: 10.3390/mi12060610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/17/2021] [Accepted: 05/21/2021] [Indexed: 12/03/2022]
Abstract
High-order harmonic generation is a nonlinear process that converts the gained energy during light-matter interaction into high-frequency radiation, thus resulting in the generation of coherent attosecond pulses in the XUV and soft x-ray regions. Here, we propose a control scheme for enhancing the efficiency of HHG process induced by an intense near-infrared (NIR) multi-cycle laser pulse. The scheme is based on introducing an infrared (IR) single-cycle pulse and exploiting its characteristic feature that manifests by a non-zero displacement effect to generate high-photon energy. The proposed scenario is numerically implemented on the basis of the time-dependent Schrödinger equation. In particular, we show that the combined pulses allow one to produce high-energy plateaus and that the harmonic cutoff is extended by a factor of 3 compared to the case with the NIR pulse alone. The emerged high-energy plateaus is understood as a result of a vast momentum transfer from the single-cycle field to the ionized electrons while travelling in the NIR field, thus leading to high-momentum electron recollisions. We also identify the role of the IR single-cycle field for controlling the directionality of the emitted electrons via the IR-field induced electron displacement effect. We further show that the emerged plateaus can be controlled by varying the relative carrier-envelope phase between the two pulses as well as the wavelengths. Our findings pave the way for an efficient control of light-matter interaction with the use of assisting femtosecond single-cycle fields.
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Affiliation(s)
- Abdelmalek Taoutioui
- Institute for Nuclear Research (ATOMKI), 4026 Debrecen, Hungary;
- Physique du Rayonnement et des Interactions Laser-Matière, Faculté des Sciences, Université Moulay Ismail, Zitoune, Meknes B.P. 11201, Morocco
| | - Hicham Agueny
- Department of Physics and Technology, University of Bergen, Allegt. 55, N-5007 Bergen, Norway
- Correspondence:
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Agueny H. Coherent electron displacement for quantum information processing using attosecond single cycle pulses. Sci Rep 2020; 10:21869. [PMID: 33318566 PMCID: PMC7736361 DOI: 10.1038/s41598-020-79004-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 12/01/2020] [Indexed: 11/09/2022] Open
Abstract
Coherent electron displacement is a conventional strategy for processing quantum information, as it enables to interconnect distinct sites in a network of atoms. The efficiency of the processing relies on the precise control of the mechanism, which has yet to be established. Here, we theoretically demonstrate a new route to drive the electron displacement on a timescale faster than that of the dynamical distortion of the electron wavepacket by utilizing attosecond single-cycle pulses. The characteristic feature of these pulses relies on a vast momentum transfer to an electron, leading to its displacement following a unidirectional path. The scenario is illustrated by revealing the spatiotemporal nature of the displaced wavepacket encoding a quantum superposition state. We map out the associated phase information and retrieve it over long distances from the origin. Moreover, we show that a sequence of such pulses applied to a chain of ions enables attosecond control of the directionality of the coherent motion of the electron wavepacket back and forth between the neighbouring sites. An extension to a two-electron spin state demonstrates the versatility of the use of these pulses. Our findings establish a promising route for advanced control of quantum states using attosecond single-cycle pulses, which pave the way towards ultrafast processing of quantum information as well as imaging.
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Affiliation(s)
- Hicham Agueny
- Department of Physics and Technology, University of Bergen, Allegt. 55, 5007, Bergen, Norway.
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Bacon DR, Gill TB, Rosamond M, Burnett AD, Dunn A, Li L, Linfield EH, Davies AG, Dean P, Freeman JR. Photoconductive arrays on insulating substrates for high-field terahertz generation. OPTICS EXPRESS 2020; 28:17219-17231. [PMID: 32679934 DOI: 10.1364/oe.391656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
We report on the design, fabrication and characterisation of large-area photoconductive THz array structures, consisting of a thin LT-GaAs active region transferred to an insulating substrate using a wafer-scale bonding process. The electrically insulating, transparent substrate reduces the parasitic currents in the devices, allowing peak THz-fields as high as 120 kV cm-1 to be generated over a bandwidth >5 THz. These results are achieved using lower pulse energies than demanded by conventional photoconductive arrays and other popular methods of generating high-field THz radiation. Two device sizes are fully characterised and the emission properties are compared to generation by optical rectification in ZnTe. The device can be operated in an optically saturated regime in order to suppress laser noise.
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High-energy electron emission from metallic nano-tips driven by intense single-cycle terahertz pulses. Nat Commun 2016; 7:13405. [PMID: 27830701 PMCID: PMC5109587 DOI: 10.1038/ncomms13405] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/29/2016] [Indexed: 11/09/2022] Open
Abstract
Electrons ejected from atoms and subsequently driven to high energies in strong laser fields enable techniques from attosecond pulse generation to imaging with rescattered electrons. Analogous processes govern strong-field electron emission from nanostructures, where long wavelength radiation and large local field enhancements hold the promise for producing electrons with substantially higher energies, allowing for higher resolution time-resolved imaging. Here we report on the use of single-cycle terahertz pulses to drive electron emission from unbiased nano-tips. Energies exceeding 5 keV are observed, substantially greater than previously attained at higher drive frequencies. Despite large differences in the magnitude of the respective local fields, we find that the maximum electron energies are only weakly dependent on the tip radius, for 10 nm<R<1,000 nm. Due to the single-cycle nature of the field, the high-energy electron emission is predicted to be confined to a single burst, potentially enabling a variety of applications. High-energy electron sources are powerful tools for investigating dynamics at atomic and subatomic scales. Here, Li and Jones demonstrate the terahertz-driven emission of electrons with energies exceeding five kiloelectronvolts from nano-tips and study its dependence on the tip radius.
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Ropagnol X, Khorasaninejad M, Raeiszadeh M, Safavi-Naeini S, Bouvier M, Côté CY, Laramée A, Reid M, Gauthier MA, Ozaki T. Intense THz Pulses with large ponderomotive potential generated from large aperture photoconductive antennas. OPTICS EXPRESS 2016; 24:11299-11311. [PMID: 27410061 DOI: 10.1364/oe.24.011299] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report the generation of free space terahertz (THz) pulses with energy up to 8.3 ± 0.2 µJ from an encapsulated interdigitated ZnSe Large Aperture Photo-Conductive Antenna (LAPCA). An aperture of 12.2 cm2 is illuminated using a 400 nm pump laser with multi-mJ energies at 10 Hz repetition rate. The calculated THz peak electric field is 331 ± 4 kV/cm with a spectrum characterized by a median frequency of 0.28 THz. Given its relatively low frequency, this THz field will accelerate charged particles efficiently having very large ponderomotive energy of 15 ± 1 eV for electrons in vacuum. The scaling of the emission is studied with respect to the dimensions of the antenna, and it is observed that the capacitance of the LAPCA leads to a severe decrease in and distortion of the biasing voltage pulse, fundamentally limiting the maximum applied bias field and consequently the maximum energy of the radiated THz pulses. In order to demonstrate the advantages of this source in the strong field regime, an open-aperture Z-scan experiment was performed on n-doped InGaAs, which showed significant absorption bleaching.
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Abstract
Femtosecond electron bunches with keV energies and eV energy spread are needed by condensed matter physicists to resolve state transitions in carbon nanotubes, molecular structures, organic salts, and charge density wave materials. These semirelativistic electron sources are not only of interest for ultrafast electron diffraction, but also for electron energy-loss spectroscopy and as a seed for x-ray FELs. Thus far, the output energy spread (hence pulse duration) of ultrafast electron guns has been limited by the achievable electric field at the surface of the emitter, which is 10 MV/m for DC guns and 200 MV/m for RF guns. A single-cycle THz electron gun provides a unique opportunity to not only achieve GV/m surface electric fields but also with relatively low THz pulse energies, since a single-cycle transform-limited waveform is the most efficient way to achieve intense electric fields. Here, electron bunches of 50 fC from a flat copper photocathode are accelerated from rest to tens of eV by a microjoule THz pulse with peak electric field of 72 MV/m at 1 kHz repetition rate. We show that scaling to the readily-available GV/m THz field regime would translate to monoenergetic electron beams of ~100 keV.
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