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Suzuki T, Zhong Y, Liu K, Kanai T, Itatani J, Okazaki K. Time- and angle-resolved photoemission spectroscopy with wavelength-tunable pump and extreme ultraviolet probe enabled by twin synchronized amplifiers. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:073001. [PMID: 38953720 DOI: 10.1063/5.0204133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 06/10/2024] [Indexed: 07/04/2024]
Abstract
We describe a setup for time- and angle-resolved photoemission spectroscopy with wavelength-tunable excitation and an extreme ultraviolet probe. It is enabled by using the 10 kHz twin Ti:sapphire amplifiers seeded by the common Ti:sapphire oscillator. The typical probe energy is 21.7 eV, and the wavelength of the pump excitation is tuned between 2400 and 1200 nm by using the optical parametric amplifier. The spectral width of the extreme ultraviolet probe is 53 meV, and the time resolution is dependent on the wavelength for the pump, better than 60 fs for the pump energy >0.7 eV. This system enables the pump energy to be matched with a specific interband transition and to probe a wider energy-momentum space. We present the results for the prototypical materials of highly oriented pyrolytic graphite and Bi2Se3 to show the performance of our system.
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Affiliation(s)
- Takeshi Suzuki
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Yigui Zhong
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Kecheng Liu
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Teruto Kanai
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Jiro Itatani
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Kozo Okazaki
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
- Material Innovation Research Center, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
- Trans-Scale Quantum Science Institute, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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2
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Spin-polarized spatially indirect excitons in a topological insulator. Nature 2023; 614:249-255. [PMID: 36755173 DOI: 10.1038/s41586-022-05567-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 11/16/2022] [Indexed: 02/10/2023]
Abstract
The exciton, a bound state of an electron and a hole, is a fundamental quasiparticle induced by coherent light-matter interactions in semiconductors. When the electrons and holes are in distinct spatial locations, spatially indirect excitons are formed with a much longer lifetime and a higher condensation temperature. One of the ultimate frontiers in this field is to create long-lived excitonic topological quasiparticles by driving exciton states with topological properties, to simultaneously leverage both topological effects and correlation1,2. Here we reveal the existence of a transient excitonic topological surface state (TSS) in a topological insulator, Bi2Te3. By using time-, spin- and angle-resolved photoemission spectroscopy, we directly follow the formation of a long-lived exciton state as revealed by an intensity buildup below the bulk-TSS mixing point and an anomalous band renormalization of the continuously connected TSS in the momentum space. Such a state inherits the spin-polarization of the TSS and is spatially indirect along the z axis, as it couples photoinduced surface electrons and bulk holes in the same momentum range, which ultimately leads to an excitonic state of the TSS. These results establish Bi2Te3 as a possible candidate for the excitonic condensation of TSSs3 and, in general, opens up a new paradigm for exploring the momentum space emergence of other spatially indirect excitons, such as moiré and quantum well excitons4-6, and for the study of non-equilibrium many-body topological physics.
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3
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Zhong H, Bao C, Lin T, Zhou S, Zhou S. A newly designed femtosecond KBe 2BO 3F 2 device with pulse duration down to 55 fs for time- and angle-resolved photoemission spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113910. [PMID: 36461493 DOI: 10.1063/5.0106864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/15/2022] [Indexed: 06/17/2023]
Abstract
Developing a widely tunable vacuum ultraviolet (VUV) source with a sub-100 fs pulse duration is critical for ultrafast pump-probe techniques such as time- and angle-resolved photoemission spectroscopy (TrARPES). While a tunable probe source with a photon energy of 5.3-7.0 eV has been recently implemented for TrARPES by using a KBe2BO3F2 (KBBF) device, the time resolution of 280-320 fs is still not ideal, which is mainly limited by the duration of the VUV probe pulse generated by the KBBF device. Here, by designing a new KBBF device, which is specially optimized for fs applications, an optimum pulse duration of 55 fs is obtained after systematic diagnostics and optimization. More importantly, a high time resolution of 81-95 fs is achieved for TrARPES measurements covering the probe photon energy range of 5.3-7.0 eV, making it particularly useful for investigating the ultrafast dynamics of quantum materials. Our work extends the application of the KBBF device to ultrafast pump-probe techniques with the advantages of both a widely tunable VUV source and ultimate time resolution.
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Affiliation(s)
- Haoyuan Zhong
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Changhua Bao
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Tianyun Lin
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Shaohua Zhou
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Shuyun Zhou
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
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4
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Bao C, Luo L, Zhang H, Zhou S, Ren Z, Zhou S. Full diagnostics and optimization of time resolution for time- and angle-resolved photoemission spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:033904. [PMID: 33820058 DOI: 10.1063/5.0044815] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/02/2021] [Indexed: 06/12/2023]
Abstract
Achieving a high time resolution is highly desirable for revealing the electron dynamics and light-induced phenomena in time- and angle-resolved photoemission spectroscopy (TrARPES). Here, we identify key factors for achieving the optimum time resolution, including laser bandwidth and optical component induced chirp. A full diagnostic scheme is constructed to characterize the pulse duration and chirp of the fundamental beam, second harmonic, and fourth harmonic, and prism pairs are used to compensate for the chirp. Moreover, by using a Sb2Te3 film as a test sample, we can achieve a high test efficiency for the time resolution during the optimization process. An optimized time resolution of 81 fs is achieved in our TrARPES system with a high repetition rate tunable from 76 to 4.75/n MHz.
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Affiliation(s)
- Changhua Bao
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Laipeng Luo
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Hongyun Zhang
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Shaohua Zhou
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Zefeng Ren
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, People's Republic of China
| | - Shuyun Zhou
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
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5
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Cucini R, Pincelli T, Panaccione G, Kopic D, Frassetto F, Miotti P, Pierantozzi GM, Peli S, Fondacaro A, De Luisa A, De Vita A, Carrara P, Krizmancic D, Payne DT, Salvador F, Sterzi A, Poletto L, Parmigiani F, Rossi G, Cilento F. Coherent narrowband light source for ultrafast photoelectron spectroscopy in the 17-31 eV photon energy range. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:014303. [PMID: 32039283 PMCID: PMC6994270 DOI: 10.1063/1.5131216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 01/13/2020] [Indexed: 05/25/2023]
Abstract
Here, we report on a novel narrowband High Harmonic Generation (HHG) light source designed for ultrafast photoelectron spectroscopy (PES) on solids. Notably, at 16.9 eV photon energy, the harmonics bandwidth equals 19 meV. This result has been obtained by seeding the HHG process with 230 fs pulses at 515 nm. The ultimate energy resolution achieved on a polycrystalline Au sample at 40 K is ∼22 meV at 16.9 eV. These parameters set a new benchmark for narrowband HHG sources and have been obtained by varying the repetition rate up to 200 kHz and, consequently, mitigating the space charge, operating with ≈ 3 × 10 7 electrons/s and ≈ 5 × 10 8 photons/s. By comparing the harmonics bandwidth and the ultimate energy resolution with a pulse duration of ∼105 fs (as retrieved from time-resolved experiments on bismuth selenide), we demonstrate a new route for ultrafast space-charge-free PES experiments on solids close to transform-limit conditions.
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Affiliation(s)
| | | | | | | | | | | | | | - Simone Peli
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste, Italy
| | | | | | - Alessandro De Vita
- Dipartimento di Fisica, Università di Milano, via Celoria 16, Milano, Italy
| | - Pietro Carrara
- Dipartimento di Fisica, Università di Milano, via Celoria 16, Milano, Italy
| | | | - Daniel T. Payne
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste, Italy
| | | | - Andrea Sterzi
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste, Italy
| | | | | | | | - Federico Cilento
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14, km 163.5, Trieste, Italy
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6
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Liu Y, Beetar JE, Hosen MM, Dhakal G, Sims C, Kabir F, Etienne MB, Dimitri K, Regmi S, Liu Y, Pathak AK, Kaczorowski D, Neupane M, Chini M. Extreme ultraviolet time- and angle-resolved photoemission setup with 21.5 meV resolution using high-order harmonic generation from a turn-key Yb:KGW amplifier. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:013102. [PMID: 32012559 DOI: 10.1063/1.5121425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/15/2019] [Indexed: 06/10/2023]
Abstract
Characterizing and controlling electronic properties of quantum materials require direct measurements of nonequilibrium electronic band structures over large regions of momentum space. Here, we demonstrate an experimental apparatus for time- and angle-resolved photoemission spectroscopy using high-order harmonic probe pulses generated by a robust, moderately high power (20 W) Yb:KGW amplifier with a tunable repetition rate between 50 and 150 kHz. By driving high-order harmonic generation (HHG) with the second harmonic of the fundamental 1025 nm laser pulses, we show that single-harmonic probe pulses at 21.8 eV photon energy can be effectively isolated without the use of a monochromator. The on-target photon flux can reach 5 × 1010 photons/s at 50 kHz, and the time resolution is measured to be 320 fs. The relatively long pulse duration of the Yb-driven HHG source allows us to reach an excellent energy resolution of 21.5 meV, which is achieved by suppressing the space-charge broadening using a low photon flux of 1.5 × 108 photons/s at a higher repetition rate of 150 kHz. The capabilities of the setup are demonstrated through measurements in the topological semimetal ZrSiS and the topological insulator Sb2-xGdxTe3.
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Affiliation(s)
- Yangyang Liu
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - John E Beetar
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Md Mofazzel Hosen
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Gyanendra Dhakal
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Christopher Sims
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Firoza Kabir
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Marc B Etienne
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Klauss Dimitri
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Sabin Regmi
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Yong Liu
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3020, USA
| | - Arjun K Pathak
- Ames Laboratory, U.S. Department of Energy, Ames, Iowa 50011-3020, USA
| | - Dariusz Kaczorowski
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, PL-50-950 Wroclaw, Poland
| | - Madhab Neupane
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Michael Chini
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
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7
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Yang Y, Tang T, Duan S, Zhou C, Hao D, Zhang W. A time- and angle-resolved photoemission spectroscopy with probe photon energy up to 6.7 eV. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:063905. [PMID: 31254991 DOI: 10.1063/1.5090439] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/04/2019] [Indexed: 06/09/2023]
Abstract
We present the development of a time- and angle-resolved photoemission spectroscopy based on a Yb-based femtosecond laser and a hemispherical electron analyzer. The energy of the pump photon is tunable between 1.4 and 1.9 eV, and the pulse duration is around 30 fs. We use a KBe2BO3F2 nonlinear optical crystal to generate probe pulses, of which the photon energy is up to 6.7 eV, and obtain an overall time resolution of 1 ps and energy resolution of 18 meV. In addition, β-BaB2O4 crystals are used to generate alternative probe pulses at 6.05 eV, giving an overall time resolution of 130 fs and energy resolution of 19 meV. We illustrate the performance of the system with representative data on several samples (Bi2Se3, YbCd2Sb2, and FeSe).
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Affiliation(s)
- Yuanyuan Yang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tianwei Tang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shaofeng Duan
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chaocheng Zhou
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Duxing Hao
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wentao Zhang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
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8
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Puppin M, Deng Y, Nicholson CW, Feldl J, Schröter NBM, Vita H, Kirchmann PS, Monney C, Rettig L, Wolf M, Ernstorfer R. Time- and angle-resolved photoemission spectroscopy of solids in the extreme ultraviolet at 500 kHz repetition rate. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:023104. [PMID: 30831759 DOI: 10.1063/1.5081938] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 01/21/2019] [Indexed: 06/09/2023]
Abstract
Time- and angle-resolved photoemission spectroscopy (trARPES) employing a 500 kHz extreme-ultraviolet light source operating at 21.7 eV probe photon energy is reported. Based on a high-power ytterbium laser, optical parametric chirped pulse amplification, and ultraviolet-driven high-harmonic generation, the light source produces an isolated high-harmonic with 110 meV bandwidth and a flux of more than 1011 photons/s on the sample. Combined with a state-of-the-art ARPES chamber, this table-top experiment allows high-repetition rate pump-probe experiments of electron dynamics in occupied and normally unoccupied (excited) states in the entire Brillouin zone and with a temporal system response function below 40 fs.
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Affiliation(s)
- M Puppin
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - Y Deng
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - C W Nicholson
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - J Feldl
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - N B M Schröter
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - H Vita
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - P S Kirchmann
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - C Monney
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - L Rettig
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - M Wolf
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
| | - R Ernstorfer
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
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9
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Spin-ARPES EUV Beamline for Ultrafast Materials Research and Development. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9030370] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A new femtosecond, Extreme Ultraviolet (EUV), Time Resolved Spin-Angle Resolved Photo-Emission Spectroscopy (TR-Spin-ARPES) beamline was developed for ultrafast materials research and development. This 50-fs laser-driven, table-top beamline is an integral part of the “Ultrafast Spintronic Materials Facility”, dedicated to engineering ultrafast materials. This facility provides a fast and in-situ analysis and development of new materials. The EUV source based on high harmonic generation process emits 2.3 × 1011 photons/second (2.3 × 108 photons/pulse) at H23 (35.7 eV) and its photon energy ranges from 10 eV to 75 eV, which enables surface sensitive studies of the electronic structure dynamics. The EUV monochromator provides the narrow bandwidth of the EUV beamline while preserving its pulse duration in an energy range of 10–100 eV. Ultrafast surface photovoltaic effect with ~650 fs rise-time was observed in p-GaAs (100) from time-resolved ARPES spectra. The data acquisition time could be reduced by over two orders of magnitude by scaling the laser driver from 1 KHz, 4W to MHz, KW average power.
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10
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Gotlieb K, Lin CY, Serbyn M, Zhang W, Smallwood CL, Jozwiak C, Eisaki H, Hussain Z, Vishwanath A, Lanzara A. Revealing hidden spin-momentum locking in a high-temperature cuprate superconductor. Science 2018; 362:1271-1275. [PMID: 30545882 DOI: 10.1126/science.aao0980] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 02/24/2018] [Accepted: 11/07/2018] [Indexed: 11/02/2022]
Abstract
Cuprate superconductors have long been thought of as having strong electronic correlations but negligible spin-orbit coupling. Using spin- and angle-resolved photoemission spectroscopy, we discovered that one of the most studied cuprate superconductors, Bi2212, has a nontrivial spin texture with a spin-momentum locking that circles the Brillouin zone center and a spin-layer locking that allows states of opposite spin to be localized in different parts of the unit cell. Our findings pose challenges for the vast majority of models of cuprates, such as the Hubbard model and its variants, where spin-orbit interaction has been mostly neglected, and open the intriguing question of how the high-temperature superconducting state emerges in the presence of this nontrivial spin texture.
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Affiliation(s)
- Kenneth Gotlieb
- Graduate Group in Applied Science and Technology, University of California, Berkeley, CA 94720, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Chiu-Yun Lin
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Maksym Serbyn
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Wentao Zhang
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Christopher L Smallwood
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Christopher Jozwiak
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Hiroshi Eisaki
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan
| | - Zahid Hussain
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | | | - Alessandra Lanzara
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. .,Department of Physics, University of California, Berkeley, CA 94720, USA
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11
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Zhou X, He S, Liu G, Zhao L, Yu L, Zhang W. New developments in laser-based photoemission spectroscopy and its scientific applications: a key issues review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:062101. [PMID: 29460857 DOI: 10.1088/1361-6633/aab0cc] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The significant progress in angle-resolved photoemission spectroscopy (ARPES) in last three decades has elevated it from a traditional band mapping tool to a precise probe of many-body interactions and dynamics of quasiparticles in complex quantum systems. The recent developments of deep ultraviolet (DUV, including ultraviolet and vacuum ultraviolet) laser-based ARPES have further pushed this technique to a new level. In this paper, we review some latest developments in DUV laser-based photoemission systems, including the super-high energy and momentum resolution ARPES, the spin-resolved ARPES, the time-of-flight ARPES, and the time-resolved ARPES. We also highlight some scientific applications in the study of electronic structure in unconventional superconductors and topological materials using these state-of-the-art DUV laser-based ARPES. Finally we provide our perspectives on the future directions in the development of laser-based photoemission systems.
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Affiliation(s)
- Xingjiang Zhou
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China. Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China
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12
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Bugini D, Boschini F, Hedayat H, Yi H, Chen C, Zhou X, Manzoni C, Dallera C, Cerullo G, Carpene E. Ultrafast spin-polarized electron dynamics in the unoccupied topological surface state of Bi 2Se 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:30LT01. [PMID: 28574404 DOI: 10.1088/1361-648x/aa76c0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The three-dimensional topological insulator Bi2Se3 presents two cone-like dispersive topological surface states centered at the [Formula: see text] point. One of them is unoccupied in equilibrium conditions and located 1.8 eV above the other one lying close to the Fermi level. In this work we employ time- and angle-resolved photoemission spectroscopy with circularly polarized pump photons to selectively track the spin dynamics of the empty topological states. We observe that spin-polarized electrons flow along the topological cone and recombine towards the unpolarized bulk states on a timescale of few tens of femtoseconds. This provides direct evidence of the capability to trigger a spin current with circularly polarized light.
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Affiliation(s)
- D Bugini
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan, 20133, Italy. Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, Via Giovanni Pascoli 70/3, Milan, 20133, Italy
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13
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Zhao Z, Kobayashi Y. Realization of a mW-level 10.7-eV (λ = 115.6 nm) laser by cascaded third harmonic generation of a Yb:fiber CPA laser at 1-MHz. OPTICS EXPRESS 2017; 25:13517-13526. [PMID: 28788895 DOI: 10.1364/oe.25.013517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 05/31/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate a 10.7-eV (λ = 115.6 nm) laser with mW levels of average power and a 1-MHz repetition rate, which was driven by the third harmonic radiation (THG), at 347 nm, of an Yb:fiber chirped pulse amplifier (CPA) laser. The 347 nm ultraviolet radiation was obtained by frequency conversion of the high power output of a 1-MHz Yb:fiber CPA, using beta barium borate (BBO) nonlinear crystals. The frequency converted output was focused down into a gas cell filled with a mixture of Ar and Xe, and was subjected to a second THG frequency conversion. The generated 10.7-eV laser was separated from the fundamental beam using a LiF prism and no further separation from other harmonic waves was required. The highest measured output power was ~80 μW, which corresponded to an average power of ~1.25 mW inside the gas cell when the transmission coefficients of the LiF optics were taken into account. The corresponding conversion efficiency from 347 nm down to 115.6 nm was ~2.5 × 10-4.
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14
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Ishida Y, Otsu T, Ozawa A, Yaji K, Tani S, Shin S, Kobayashi Y. High repetition pump-and-probe photoemission spectroscopy based on a compact fiber laser system. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:123902. [PMID: 28040935 DOI: 10.1063/1.4969053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The paper describes a time-resolved photoemission (TRPES) apparatus equipped with a Yb-doped fiber laser system delivering 1.2-eV pump and 5.9-eV probe pulses at the repetition rate of 95 MHz. Time and energy resolutions are 11.3 meV and ∼310 fs, respectively, the latter is estimated by performing TRPES on a highly oriented pyrolytic graphite (HOPG). The high repetition rate is suited for achieving high signal-to-noise ratio in TRPES spectra, thereby facilitating investigations of ultrafast electronic dynamics in the low pump fluence (p) region. TRPES of polycrystalline bismuth (Bi) at p as low as 30 nJ/mm2 is demonstrated. The laser source is compact and is docked to an existing TRPES apparatus based on a 250-kHz Ti:sapphire laser system. The 95-MHz system is less prone to space-charge broadening effects compared to the 250-kHz system, which we explicitly show in a systematic probe-power dependency of the Fermi cutoff of polycrystalline gold. We also describe that the TRPES response of an oriented Bi(111)/HOPG sample is useful for fine-tuning the spatial overlap of the pump and probe beams even when p is as low as 30 nJ/mm2.
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Affiliation(s)
- Y Ishida
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - T Otsu
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - A Ozawa
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - K Yaji
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - S Tani
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - S Shin
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - Y Kobayashi
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
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15
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Zhang W, Miller T, Smallwood CL, Yoshida Y, Eisaki H, Kaindl RA, Lee DH, Lanzara A. Stimulated emission of Cooper pairs in a high-temperature cuprate superconductor. Sci Rep 2016; 6:29100. [PMID: 27364682 PMCID: PMC4929572 DOI: 10.1038/srep29100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 06/15/2016] [Indexed: 11/09/2022] Open
Abstract
The concept of stimulated emission of bosons has played an important role in modern science and technology, and constitutes the working principle for lasers. In a stimulated emission process, an incoming photon enhances the probability that an excited atomic state will transition to a lower energy state and generate a second photon of the same energy. It is expected, but not experimentally shown, that stimulated emission contributes significantly to the zero resistance current in a superconductor by enhancing the probability that scattered Cooper pairs will return to the macroscopically occupied condensate instead of entering any other state. Here, we use time- and angle-resolved photoemission spectroscopy to study the initial rise of the non-equilibrium quasiparticle population in a Bi2Sr2CaCu2O8+δ cuprate superconductor induced by an ultrashort laser pulse. Our finding reveals significantly slower buildup of quasiparticles in the superconducting state than in the normal state. The slower buildup only occurs when the pump pulse is too weak to deplete the superconducting condensate, and for cuts inside the Fermi arc region. We propose this is a manifestation of stimulated recombination of broken Cooper pairs, and signals an important momentum space dichotomy in the formation of Cooper pairs inside and outside the Fermi arc region.
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Affiliation(s)
- Wentao Zhang
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tristan Miller
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Physics, University of California, Berkeley, California 94720, USA
| | - Christopher L Smallwood
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Physics, University of California, Berkeley, California 94720, USA
| | - Yoshiyuki Yoshida
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8568, Japan
| | - Hiroshi Eisaki
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8568, Japan
| | - R A Kaindl
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Dung-Hai Lee
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Physics, University of California, Berkeley, California 94720, USA
| | - Alessandra Lanzara
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Physics, University of California, Berkeley, California 94720, USA
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16
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Boschini F, Hedayat H, Dallera C, Farinello P, Manzoni C, Magrez A, Berger H, Cerullo G, Carpene E. An innovative Yb-based ultrafast deep ultraviolet source for time-resolved photoemission experiments. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:123903. [PMID: 25554305 DOI: 10.1063/1.4903347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Time- and angle-resolved photoemission spectroscopy is a powerful technique to study ultrafast electronic dynamics in solids. Here, an innovative optical setup based on a 100-kHz Yb laser source is presented. Exploiting non-collinear optical parametric amplification and sum-frequency generation, ultrashort pump (hν = 1.82 eV) and ultraviolet probe (hν = 6.05 eV) pulses are generated. Overall temporal and instrumental energy resolutions of, respectively, 85 fs and 50 meV are obtained. Time- and angle-resolved measurements on BiTeI semiconductor are presented to show the capabilities of the setup.
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Affiliation(s)
- F Boschini
- Dipartimento di Fisica, Politecnico di Milano, 20133 Milan, Italy
| | - H Hedayat
- Dipartimento di Fisica, Politecnico di Milano, 20133 Milan, Italy
| | - C Dallera
- Dipartimento di Fisica, Politecnico di Milano, 20133 Milan, Italy
| | - P Farinello
- Dipartimento di Ingegneria Industriale e dell'Informazione, Università di Pavia, 27100 Pavia, Italy
| | - C Manzoni
- IFN-CNR Dipartimento di Fisica, Politecnico di Milano, 20133 Milan, Italy
| | - A Magrez
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - H Berger
- Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - G Cerullo
- Dipartimento di Fisica, Politecnico di Milano, 20133 Milan, Italy
| | - E Carpene
- IFN-CNR Dipartimento di Fisica, Politecnico di Milano, 20133 Milan, Italy
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17
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Ishida Y, Togashi T, Yamamoto K, Tanaka M, Kiss T, Otsu T, Kobayashi Y, Shin S. Time-resolved photoemission apparatus achieving sub-20-meV energy resolution and high stability. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:123904. [PMID: 25554306 DOI: 10.1063/1.4903788] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The paper describes a time- and angle-resolved photoemission apparatus consisting of a hemispherical analyzer and a pulsed laser source. We demonstrate 1.48-eV pump and 5.92-eV probe measurements at the ⩾10.5-meV and ⩾240-fs resolutions by use of fairly monochromatic 170-fs pulses delivered from a regeneratively amplified Ti:sapphire laser system operating typically at 250 kHz. The apparatus is capable to resolve the optically filled superconducting peak in the unoccupied states of a cuprate superconductor, Bi2Sr2CaCu2O(8 + δ). A dataset recorded on Bi(111) surface is also presented. Technical descriptions include the followings: A simple procedure to fine-tune the spatio-temporal overlap of the pump-and-probe beams and their diameters; achieving a long-term stability of the system that enables a normalization-free dataset acquisition; changing the repetition rate by utilizing acoustic optical modulator and frequency-division circuit.
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Affiliation(s)
- Y Ishida
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - T Togashi
- RIKEN SPring-8 Center, Sayo, Sayo, Hyogo 679-5148, Japan
| | - K Yamamoto
- RIKEN SPring-8 Center, Sayo, Sayo, Hyogo 679-5148, Japan
| | - M Tanaka
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - T Kiss
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - T Otsu
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - Y Kobayashi
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
| | - S Shin
- ISSP, University of Tokyo, Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan
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18
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Ultrafast quenching of electron–boson interaction and superconducting gap in a cuprate superconductor. Nat Commun 2014; 5:4959. [DOI: 10.1038/ncomms5959] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 08/11/2014] [Indexed: 01/24/2023] Open
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