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Wang Z, Halati CM, Bernier JS, Ponomaryov A, Gorbunov DI, Niesen S, Breunig O, Klopf JM, Zvyagin S, Lorenz T, Loidl A, Kollath C. Experimental observation of repulsively bound magnons. Nature 2024; 631:760-764. [PMID: 38926581 DOI: 10.1038/s41586-024-07599-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
Stable composite objects, such as hadrons, nuclei, atoms, molecules and superconducting pairs, formed by attractive forces are ubiquitous in nature. By contrast, composite objects stabilized by means of repulsive forces were long thought to be theoretical constructions owing to their fragility in naturally occurring systems. Surprisingly, the formation of bound atom pairs by strong repulsive interactions has been demonstrated experimentally in optical lattices1. Despite this success, repulsively bound particle pairs were believed to have no analogue in condensed matter owing to strong decay channels. Here we present spectroscopic signatures of repulsively bound three-magnon states and bound magnon pairs in the Ising-like chain antiferromagnet BaCo2V2O8. In large transverse fields, below the quantum critical point, we identify repulsively bound magnon states by comparing terahertz spectroscopy measurements to theoretical results for the Heisenberg-Ising chain antiferromagnet, a paradigmatic quantum many-body model2-5. Our experimental results show that these high-energy, repulsively bound magnon states are well separated from continua, exhibit notable dynamical responses and, despite dissipation, are sufficiently long-lived to be identified. As the transport properties in spin chains can be altered by magnon bound states, we envision that such states could serve as resources for magnonics-based quantum information processing technologies6-8.
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Affiliation(s)
- Zhe Wang
- Department of Physics, TU Dortmund University, Dortmund, Germany.
- Institute of Physics II, University of Cologne, Cologne, Germany.
- Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, Augsburg, Germany.
| | - Catalin-Mihai Halati
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland
- Physikalisches Institut, University of Bonn, Bonn, Germany
| | - Jean-Sébastien Bernier
- Physikalisches Institut, University of Bonn, Bonn, Germany
- Department of Physics, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Alexey Ponomaryov
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
| | - Denis I Gorbunov
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
| | - Sandra Niesen
- Institute of Physics II, University of Cologne, Cologne, Germany
| | - Oliver Breunig
- Institute of Physics II, University of Cologne, Cologne, Germany
| | - J Michael Klopf
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
| | - Sergei Zvyagin
- Dresden High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
| | - Thomas Lorenz
- Institute of Physics II, University of Cologne, Cologne, Germany
| | - Alois Loidl
- Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, Augsburg, Germany
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Moseley DH, Liu Z, Bone AN, Stavretis SE, Singh SK, Atanasov M, Lu Z, Ozerov M, Thirunavukkuarasu K, Cheng Y, Daemen LL, Lubert-Perquel D, Smirnov D, Neese F, Ramirez-Cuesta AJ, Hill S, Dunbar KR, Xue ZL. Comprehensive Studies of Magnetic Transitions and Spin-Phonon Couplings in the Tetrahedral Cobalt Complex Co(AsPh 3) 2I 2. Inorg Chem 2022; 61:17123-17136. [PMID: 36264658 DOI: 10.1021/acs.inorgchem.2c02604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A combination of inelastic neutron scattering (INS), far-IR magneto-spectroscopy (FIRMS), and Raman magneto-spectroscopy (RaMS) has been used to comprehensively probe magnetic excitations in Co(AsPh3)2I2 (1), a reported single-molecule magnet (SMM). With applied field, the magnetic zero-field splitting (ZFS) peak (2D') shifts to higher energies in each spectroscopy. INS placed the ZFS peak at 54 cm-1, as revealed by both variable-temperature (VT) and variable-magnetic-field data, giving results that agree well with those from both far-IR and Raman studies. Both FIRMS and RaMS also reveal the presence of multiple spin-phonon couplings as avoided crossings with neighboring phonons. Here, phonons refer to both intramolecular and lattice vibrations. The results constitute a rare case in which the spin-phonon couplings are observed with both Raman-active (g modes) and far-IR-active phonons (u modes; space group P21/c, no. 14, Z = 4 for 1). These couplings are fit using a simple avoided crossing model with coupling constants of ca. 1-2 cm-1. The combined spectroscopies accurately determine the magnetic excited level and the interaction of the magnetic excitation with phonon modes. Density functional theory (DFT) phonon calculations compare well with INS, allowing for the assignment of the modes and their symmetries. Electronic calculations elucidate the nature of ZFS in the complex. Features of different techniques to determine ZFS and other spin-Hamiltonian parameters in transition-metal complexes are summarized.
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Affiliation(s)
- Duncan H Moseley
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Zhiming Liu
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Alexandria N Bone
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Shelby E Stavretis
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, 502285Sangareddy, Telangana, India
| | - Mihail Atanasov
- Max Planck Institute for Coal Research, Kaiser-Wilhelm-Platz 1, D-45470Mülheim an der Ruhr, Germany.,Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113Sofia, Bulgaria
| | - Zhengguang Lu
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States
| | | | - Yongqiang Cheng
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Luke L Daemen
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Daphné Lubert-Perquel
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States
| | - Dmitry Smirnov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States
| | - Frank Neese
- Max Planck Institute for Coal Research, Kaiser-Wilhelm-Platz 1, D-45470Mülheim an der Ruhr, Germany
| | - A J Ramirez-Cuesta
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee37831, United States
| | - Stephen Hill
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida32310, United States.,Department of Physics, Florida State University, Tallahassee, Florida32306, United States
| | - Kim R Dunbar
- Department of Chemistry, Texas A&M University, College Station, Texas77843, United States
| | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
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Novikov VV, Nelyubina YV. Modern physical methods for the molecular design of single-molecule magnets. RUSSIAN CHEMICAL REVIEWS 2021. [DOI: 10.1070/rcr5002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
Many paramagnetic metal complexes have emerged as unique magnetic materials (single-molecule magnets), which behave as conventional magnets at the single-molecule level, thereby making it possible to use them in modern devices for data storage and processing. The rational design of these complexes, however, requires a deep understanding of the physical laws behind a single-molecule magnet behaviour, the mechanisms of magnetic relaxation that determines the magnetic properties and the relationship of these properties with the structure of single-molecule magnets. This review focuses on the physical methods providing such understanding, including different versions and various combinations of magnetometry, electron paramagnetic and nuclear magnetic resonance spectroscopy, optical spectroscopy and X-ray diffraction. Many of these methods are traditionally used to determine the composition and structure of new chemical compounds. However, they are rarely applied to study molecular magnetism.
The bibliography includes 224 references.
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Moseley DH, Stavretis SE, Zhu Z, Guo M, Brown CM, Ozerov M, Cheng Y, Daemen LL, Richardson R, Knight G, Thirunavukkuarasu K, Ramirez-Cuesta AJ, Tang J, Xue ZL. Inter-Kramers Transitions and Spin-Phonon Couplings in a Lanthanide-Based Single-Molecule Magnet. Inorg Chem 2020; 59:5218-5230. [PMID: 32196322 PMCID: PMC7935416 DOI: 10.1021/acs.inorgchem.0c00523] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Spin-phonon coupling plays a critical role in magnetic relaxation in single-molecule magnets (SMMs) and molecular qubits. Yet, few studies of its nature have been conducted. Phonons here refer to both intermolecular and intramolecular vibrations. In the current work, we show spin-phonon couplings between IR-active phonons in a lanthanide molecular complex and Kramers doublets (from the crystal field). For the SMM Er[N(SiMe3)2]3 (1, Me = methyl), the couplings are observed in the far-IR magnetospectroscopy (FIRMS) of crystals with coupling constants ≈ 2-3 cm-1. In particular, one of the magnetic excitations couples to at least two phonon excitations. The FIRMS reveals at least three magnetic excitations (within the 4I15/2 ground state/manifold; hereafter, manifold) at 0 T at 104, ∼180, and 245 cm-1, corresponding to transitions from the ground state, MJ = ±15/2, to the first three excited states, MJ = ±13/2, ±11/2, and ±9/2, respectively. The transition between the ground and first excited Kramers doublet in 1 is also observed in inelastic neutron scattering (INS) spectroscopy, moving to a higher energy with an increasing magnetic field. INS also gives complete phonon spectra of 1. Periodic DFT computations provide the energies of all phonon excitations, which compare well with the spectra from INS, supporting the assignment of the inter-Kramers doublet (magnetic) transitions in the spectra. The current studies unveil and measure the spin-phonon couplings in a typical lanthanide complex and throw light on the origin of the spin-phonon entanglement.
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Affiliation(s)
- Duncan H Moseley
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Shelby E Stavretis
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Zhenhua Zhu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Mei Guo
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Craig M Brown
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Yongqiang Cheng
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Luke L Daemen
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Rachael Richardson
- Department of Physics, Florida A&M University, Tallahassee, Florida 32307, United States
| | - Gary Knight
- Department of Physics, Florida A&M University, Tallahassee, Florida 32307, United States
| | | | - Anibal J Ramirez-Cuesta
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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Qi X, Xiao H, Han X, Wang Z, Xia D, Wang P, Li L. A broad range frequency measurement method for continuous and pulsed THz waves. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:014710. [PMID: 32012550 DOI: 10.1063/1.5120592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 01/07/2020] [Indexed: 06/10/2023]
Abstract
This paper proposes a method to measure the frequency of terahertz (THz) waves based on the Zeeman effect and the high magnetic field technology with a wideband range from 60 GHz to 3 THz. As the frequency of THz waves absorbed by the sample is linear to the magnetic field in the Zeeman effect, the frequency can be measured by the magnetic field strength. A comparison study of THz frequency measurement was carried out in two magnet systems (a superconducting one and a pulsed one) to investigate the performance in two kinds of high magnetic fields. The experimental results of 60-700 GHz show that this method has high resolution (about 0.001%), excellent linearity, and good repeatability. Moreover, the proposed method can measure polychromatic signals simultaneously as well as the single pulse frequency in the order of tens of microseconds.
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Affiliation(s)
- Xin Qi
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Houxiu Xiao
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaotao Han
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhenxing Wang
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Donghui Xia
- School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Pengbo Wang
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Liang Li
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
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6
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Tanaka T. Difference frequency generation in free electron lasers. OPTICS LETTERS 2018; 43:4485-4488. [PMID: 30211896 DOI: 10.1364/ol.43.004485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 08/27/2018] [Indexed: 06/08/2023]
Abstract
We propose a simple scheme for difference frequency generation in free electron lasers (FELs), in which the electron beam interacts with a dual-frequency laser and emits intense coherent radiation at the difference frequency. We analytically show that the microbunch formation in the electron beam, which is the most important process in FELs, is dominated by nonlinear wave mixing in the proposed scheme. Numerical examples of applying the proposed scheme to generating terahertz radiation are presented as one of the most important applications.
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Veber SL, Tumanov SV, Fursova EY, Shevchenko OA, Getmanov YV, Scheglov MA, Kubarev VV, Shevchenko DA, Gorbachev II, Salikova TV, Kulipanov GN, Ovcharenko VI, Fedin MV. X-band EPR setup with THz light excitation of Novosibirsk Free Electron Laser: Goals, means, useful extras. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 288:11-22. [PMID: 29360045 DOI: 10.1016/j.jmr.2018.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/10/2018] [Accepted: 01/11/2018] [Indexed: 06/07/2023]
Abstract
Electron Paramagnetic Resonance (EPR) station at the Novosibirsk Free Electron Laser (NovoFEL) user facility is described. It is based on X-band (∼9 GHz) EPR spectrometer and operates in both Continuous Wave (CW) and Time-Resolved (TR) modes, each allowing detection of either direct or indirect influence of high-power NovoFEL light (THz and mid-IR) on the spin system under study. The optics components including two parabolic mirrors, shutters, optical chopper and multimodal waveguide allow the light of NovoFEL to be directly fed into the EPR resonator. Characteristics of the NovoFEL radiation, the transmission and polarization-retaining properties of the waveguide used in EPR experiments are presented. The types of proposed experiments accessible using this setup are sketched. In most practical cases the high-power radiation applied to the sample induces its rapid temperature increase (T-jump), which is best visible in TR mode. Although such influence is a by-product of THz radiation, this thermal effect is controllable and can deliberately be used to induce and measure transient signals of arbitrary samples. The advantage of tunable THz radiation is the absence of photo-induced processes in the sample and its high penetration ability, allowing fast heating of a large portion of virtually any sample and inducing intense transients. Such T-jump TR EPR spectroscopy with THz pulses has been previewed for the two test samples, being a useful supplement for the main goals of the created setup.
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Affiliation(s)
- Sergey L Veber
- International Tomography Center, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia.
| | - Sergey V Tumanov
- International Tomography Center, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia
| | - Elena Yu Fursova
- International Tomography Center, SB RAS, Novosibirsk 630090, Russia
| | - Oleg A Shevchenko
- Budker Institute of Nuclear Physics, SB RAS, Novosibirsk 630090, Russia
| | | | | | - Vitaly V Kubarev
- Novosibirsk State University, Novosibirsk 630090, Russia; Budker Institute of Nuclear Physics, SB RAS, Novosibirsk 630090, Russia
| | | | | | | | | | | | - Matvey V Fedin
- International Tomography Center, SB RAS, Novosibirsk 630090, Russia; Novosibirsk State University, Novosibirsk 630090, Russia
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Malvestuto M, Ciprian R, Caretta A, Casarin B, Parmigiani F. Ultrafast magnetodynamics with free-electron lasers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:053002. [PMID: 29315080 DOI: 10.1088/1361-648x/aaa211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The study of ultrafast magnetodynamics has entered a new era thanks to the groundbreaking technological advances in free-electron laser (FEL) light sources. The advent of these light sources has made possible unprecedented experimental schemes for time-resolved x-ray magneto-optic spectroscopies, which are now paving the road for exploring the ultimate limits of out-of-equilibrium magnetic phenomena. In particular, these studies will provide insights into elementary mechanisms governing spin and orbital dynamics, therefore contributing to the development of ultrafast devices for relevant magnetic technologies. This topical review focuses on recent advancement in the study of non-equilibrium magnetic phenomena from the perspective of time-resolved extreme ultra violet (EUV) and soft x-ray spectroscopies at FELs with highlights of some important experimental results.
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Affiliation(s)
- Marco Malvestuto
- Elettra-Sincrotrone Trieste S.C.p.A. Strada Statale 14-km 163.5 in AREA Science Park 34149 Basovizza, Trieste, Italy
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Nehrkorn J, Holldack K, Bittl R, Schnegg A. Recent progress in synchrotron-based frequency-domain Fourier-transform THz-EPR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 280:10-19. [PMID: 28579095 DOI: 10.1016/j.jmr.2017.04.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/30/2017] [Accepted: 04/01/2017] [Indexed: 06/07/2023]
Abstract
We describe frequency-domain Fourier-transform THz-EPR as a method to assign spin-coupling parameters of high-spin (S>1/2) systems with very large zero-field splittings. The instrumental foundations of synchrotron-based FD-FT THz-EPR are presented, alongside with a discussion of frequency-domain EPR simulation routines. The capabilities of this approach is demonstrated for selected mono- and multinuclear HS systems. Finally, we discuss remaining challenges and give an outlook on the future prospects of the technique.
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Affiliation(s)
- Joscha Nehrkorn
- Berlin Joint EPR Lab, Institute for Nanospectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie, Kekuléstraβe 5, 12489 Berlin, Germany; Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195, United States
| | - Karsten Holldack
- Institute Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Robert Bittl
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Alexander Schnegg
- Berlin Joint EPR Lab, Institute for Nanospectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie, Kekuléstraβe 5, 12489 Berlin, Germany.
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Liu B, Bromberger H, Cartella A, Gebert T, Först M, Cavalleri A. Generation of narrowband, high-intensity, carrier-envelope phase-stable pulses tunable between 4 and 18 THz. OPTICS LETTERS 2017; 42:129-131. [PMID: 28059195 DOI: 10.1364/ol.42.000129] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We report on the generation of high-energy (1.9 μJ) far-infrared pulses tunable between 4 and 18 THz frequency. Emphasis is placed on tunability and on minimizing the bandwidth of these pulses to less than 1 THz, as achieved by difference-frequency mixing of two linearly chirped near-infrared pulses in the organic nonlinear crystal DSTMS. As the two near-infrared pulses are derived from amplification of the same white light continuum, their carrier envelope phase fluctuations are mutually correlated, and hence the difference-frequency THz field exhibits absolute phase stability. This source opens up new possibilities for the control of condensed matter and chemical systems by selective excitation of low-energy modes in a frequency range that has, to date, been difficult to access.
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11
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Krzystek J, Telser J. Measuring giant anisotropy in paramagnetic transition metal complexes with relevance to single-ion magnetism. Dalton Trans 2016; 45:16751-16763. [DOI: 10.1039/c6dt01754a] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
“Giant magnetic anisotropy” is a phenomenon identified in certain coordination complexes of nd- and nf-block ions. The strengths and weaknesses of multiple methods used to measure it are evaluated.
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Affiliation(s)
- J. Krzystek
- National High Magnetic Field Laboratory
- Florida State University
- Tallahassee
- USA
| | - Joshua Telser
- Department of Biological
- Chemical and Physical Sciences
- Roosevelt University
- Chicago
- USA
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Terahertz field control of in-plane orbital order in La(0.5)Sr(1.5)MnO4. Nat Commun 2015; 6:8175. [PMID: 26381700 PMCID: PMC4595605 DOI: 10.1038/ncomms9175] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 07/27/2015] [Indexed: 11/20/2022] Open
Abstract
In-plane anisotropic ground states are ubiquitous in correlated solids such as pnictides, cuprates and manganites. They can arise from doping Mott insulators and compete with phases such as superconductivity; however, their origins are debated. Strong coupling between lattice, charge, orbital and spin degrees of freedom results in simultaneous ordering of multiple parameters, masking the mechanism that drives the transition. Here we demonstrate that the orbital domains in a manganite can be oriented by the polarization of a pulsed THz light field. Through the application of a Hubbard model, we show that domain control can be achieved by enhancing the local Coulomb interactions, which drive domain reorientation. Our results highlight the key role played by the Coulomb interaction in the control and manipulation of orbital order in the manganites and demonstrate a new way to use THz to understand and manipulate anisotropic phases in a potentially broad range of correlated materials. Numerous correlated materials exhibit an in-plane anisotropic ground state but their origin is unclear. Here the authors control the orientation of orbital domains in a manganite using the polarization of terahertz pulses, which can be explained by field-induced enhancement of the electron interactions.
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Schmidt J, Winnerl S, Seidel W, Bauer C, Gensch M, Schneider H, Helm M. Single-pulse picking at kHz repetition rates using a Ge plasma switch at the free-electron laser FELBE. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2015; 86:063103. [PMID: 26133824 DOI: 10.1063/1.4921864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrate a system for picking of mid-infrared and terahertz (THz) radiation pulses from the free-electron laser (FEL) FELBE operating at a repetition rate of 13 MHz. Single pulses are reflected by a dense electron-hole plasma in a Ge slab that is photoexcited by amplified near-infrared (NIR) laser systems operating at repetition rates of 1 kHz and 100 kHz, respectively. The peak intensity of picked pulses is up to 400 times larger than the peak intensity of residual pulses. The required NIR fluence for picking pulses at wavelengths in the range from 5 μm to 30 μm is discussed. In addition, we show that the reflectivity of the plasma decays on a time scale from 100 ps to 1 ns dependent on the wavelengths of the FEL and the NIR laser. The plasma switch enables experiments with the FEL that require high peak power but lower average power. Furthermore, the system is well suited to investigate processes with decay times in the μs to ms regime, i.e., much longer than the 77 ns long pulse repetition period of FELBE.
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Affiliation(s)
- J Schmidt
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
| | - S Winnerl
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
| | - W Seidel
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
| | - C Bauer
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
| | - M Gensch
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
| | - H Schneider
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
| | - M Helm
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
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Nehrkorn J, Schnegg A, Holldack K, Stoll S. General magnetic transition dipole moments for electron paramagnetic resonance. PHYSICAL REVIEW LETTERS 2015; 114:010801. [PMID: 25615456 DOI: 10.1103/physrevlett.114.010801] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Indexed: 06/04/2023]
Abstract
We present general expressions for the magnetic transition rates in electron paramagnetic resonance (EPR) experiments of anisotropic spin systems in the solid state. The expressions apply to general spin centers and arbitrary excitation geometry (Voigt, Faraday, and intermediate). They work for linear and circular polarized as well as unpolarized excitation, and for crystals and powders. The expressions are based on the concept of the (complex) magnetic transition dipole moment vector. Using the new theory, we determine the parities of ground and excited spin states of high-spin (S=5/2) Fe(III) in hemin from the polarization dependence of experimental EPR line intensities.
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Affiliation(s)
- Joscha Nehrkorn
- Berlin Joint EPR Laboratory, Institut für Silizium-Photovoltaik, Helmholtz-Zentrum Berlin für Materialien und Energie, D-12489 Berlin, Germany
| | - Alexander Schnegg
- Berlin Joint EPR Laboratory, Institut für Silizium-Photovoltaik, Helmholtz-Zentrum Berlin für Materialien und Energie, D-12489 Berlin, Germany
| | - Karsten Holldack
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, D-12489 Berlin, Germany
| | - Stefan Stoll
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
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15
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Ozerov M, Romhányi J, Belesi M, Berger H, Ansermet JP, van den Brink J, Wosnitza J, Zvyagin SA, Rousochatzakis I. Establishing the fundamental magnetic interactions in the chiral Skyrmionic Mott insulator Cu(2)OSeO(3) by terahertz electron spin resonance. PHYSICAL REVIEW LETTERS 2014; 113:157205. [PMID: 25375739 DOI: 10.1103/physrevlett.113.157205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Indexed: 05/26/2023]
Abstract
The recent discovery of Skyrmions in Cu(2)OSeO(3) has established a new platform to create and manipulate Skyrmionic spin textures. We use high-field electron spin resonance with a terahertz free-electron laser and pulsed magnetic fields up to 64 T to probe and quantify its microscopic spin-spin interactions. In addition to the previously observed long-wavelength Goldstone mode, this technique probes also the high-energy part of the excitation spectrum which is inaccessible by standard low-frequency electron spin resonance. Fitting the behavior of the observed modes in magnetic field to a theoretical framework establishes experimentally that the fundamental magnetic building blocks of this Skyrmionic magnet are rigid, highly entangled and weakly coupled tetrahedra.
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Affiliation(s)
- M Ozerov
- Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, Dresden D-01328, Germany
| | - J Romhányi
- Leibniz Institute for Solid State and Materials Research, IFW, Dresden D-01069, Germany
| | - M Belesi
- Leibniz Institute for Solid State and Materials Research, IFW, Dresden D-01069, Germany
| | - H Berger
- Institut de Physique de la Matiére Condensée, Ecole Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne-EPFL, Switzerland
| | - J-Ph Ansermet
- Institut de Physique de la Matiére Condensée, Ecole Polytechnique Fédérale de Lausanne, Station 3, CH-1015 Lausanne-EPFL, Switzerland
| | - Jeroen van den Brink
- Leibniz Institute for Solid State and Materials Research, IFW, Dresden D-01069, Germany and Department of Physics, TU Dresden, Dresden D-01062, Germany
| | - J Wosnitza
- Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, Dresden D-01328, Germany and Department of Physics, TU Dresden, Dresden D-01062, Germany
| | - S A Zvyagin
- Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, Dresden D-01328, Germany
| | - I Rousochatzakis
- Leibniz Institute for Solid State and Materials Research, IFW, Dresden D-01069, Germany
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16
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Zvyagin SA, Kamenskyi D, Ozerov M, Wosnitza J, Ikeda M, Fujita T, Hagiwara M, Smirnov AI, Soldatov TA, Shapiro AY, Krzystek J, Hu R, Ryu H, Petrovic C, Zhitomirsky ME. Direct determination of exchange parameters in Cs2CuBr4 and Cs2CuCl4: high-field electron-spin-resonance studies. PHYSICAL REVIEW LETTERS 2014; 112:077206. [PMID: 24579634 DOI: 10.1103/physrevlett.112.077206] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Indexed: 06/03/2023]
Abstract
Spin-1/2 Heisenberg antiferromagnets Cs2CuCl4 and Cs2CuBr4 with distorted triangular-lattice structures are studied by means of electron spin resonance spectroscopy in magnetic fields up to the saturation field and above. In the magnetically saturated phase, quantum fluctuations are fully suppressed, and the spin dynamics is defined by ordinary magnons. This allows us to accurately describe the magnetic excitation spectra in both materials and, using the harmonic spin-wave theory, to determine their exchange parameters. The viability of the proposed method was proven by applying it to Cs2CuCl4, yielding J/kB=4.7(2) K, J'/kB=1.42(7) K, [J'/J≃0.30] and revealing good agreement with inelastic neutron-scattering results. For the isostructural Cs2CuBr4, we obtain J/kB=14.9(7) K, J'/kB=6.1(3) K, [J'/J≃0.41], providing exact and conclusive information on the exchange couplings in this frustrated spin system.
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Affiliation(s)
- S A Zvyagin
- Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - D Kamenskyi
- Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - M Ozerov
- Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - J Wosnitza
- Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany and Institüt fur Festkörperphysik, TU Dresden, 01068 Dresden, Germany
| | - M Ikeda
- KYOKUGEN, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - T Fujita
- KYOKUGEN, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - M Hagiwara
- KYOKUGEN, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - A I Smirnov
- P.L. Kapitza Institute for Physical Problems, RAS, 119334 Moscow, Russia
| | - T A Soldatov
- Moscow Institute for Physics and Technology, 141700 Dolgoprudnyi, Russia
| | - A Ya Shapiro
- A.V. Shubnikov Institute of Crystallography, RAS, 119333, Moscow, Russia
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, USA
| | - R Hu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - H Ryu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA and Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
| | - C Petrovic
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA and Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
| | - M E Zhitomirsky
- Service de Physique Statistique, Magnétisme et Supraconductivité, UMR-E9001 CEA-INAC/UJF, 38054 Grenoble Cedex 9, France
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Veber SL, Fedin MV, Maryunina KY, Boldyrev KN, Sheglov MA, Kubarev VV, Shevchenko OA, Vinokurov NA, Kulipanov GN, Sagdeev RZ, Ovcharenko VI, Bagryanskaya EG. Influence of Intense THz Radiation on Spin State of Photoswitchable Compound Cu(hfac)2LPr. J Phys Chem A 2013; 117:1483-91. [DOI: 10.1021/jp311404t] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Sergey L. Veber
- International Tomography Center, SB RAS, 630090 Novosibirsk, Russia
| | - Matvey V. Fedin
- International Tomography Center, SB RAS, 630090 Novosibirsk, Russia
| | | | | | | | - Vitaly V. Kubarev
- Budker Institute of Nuclear Physics, SB RAS, 630090 Novosibirsk, Russia
- Novosibirsk State University, Novosibirsk 630090, Russia
| | | | | | | | - Renad Z. Sagdeev
- International Tomography Center, SB RAS, 630090 Novosibirsk, Russia
| | | | - Elena G. Bagryanskaya
- International Tomography Center, SB RAS, 630090 Novosibirsk, Russia
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, SB RAS,
630090 Novosibirsk, Russia
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Eaton SS, Eaton GR. The world as viewed by and with unpaired electrons. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 223:151-63. [PMID: 22975244 PMCID: PMC3496796 DOI: 10.1016/j.jmr.2012.07.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 07/26/2012] [Accepted: 07/27/2012] [Indexed: 06/01/2023]
Abstract
Recent advances in electron paramagnetic resonance (EPR) include capabilities for applications to areas as diverse as archeology, beer shelf life, biological structure, dosimetry, in vivo imaging, molecular magnets, and quantum computing. Enabling technologies include multifrequency continuous wave, pulsed, and rapid scan EPR. Interpretation is enhanced by increasingly powerful computational models.
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Affiliation(s)
- Sandra S Eaton
- Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80208, USA
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Sakurai T, Fujimoto K, Goto R, Okubo S, Ohta H, Uwatoko Y. Development of high-pressure and high-field ESR system using SQUID magnetometer. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 223:41-45. [PMID: 22967886 DOI: 10.1016/j.jmr.2012.07.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 07/24/2012] [Accepted: 07/25/2012] [Indexed: 06/01/2023]
Abstract
We have developed a high-pressure and high-field electron spin resonance (ESR) system using the combination of a commercially available superconducting quantum interference device (SQUID) magnetometer and a clamp-type piston cylinder pressure cell. The magnetic field range is up to 5 T, and the maximum pressure reaches 1.5 GPa. The most characteristic feature of this system is its easy handling as compared with other high-pressure ESR systems. Moreover, the macroscopic magnetization measurement can be performed simultaneously with the microscopic ESR measurement. In addition to these features, the well-established pressure calibration method utilizing the change of superconducting transition temperature of tin can be applied to this system. By using this system, we obtained pressure dependence of the single ion magnetic anisotropy parameter D of NiSnCl(6)·6H(2)O up to 1.5 GPa precisely, and the magnetization behavior of this material under pressure was explained well by its pressure dependence of the D value.
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Affiliation(s)
- T Sakurai
- Center for Supports to Research and Education Activities, Kobe University, Nada, Kobe 657-8501, Japan.
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Meier B, Kohlrautz J, Haase J, Braun M, Wolff-Fabris F, Kampert E, Herrmannsdörfer T, Wosnitza J. Nuclear magnetic resonance apparatus for pulsed high magnetic fields. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:083113. [PMID: 22938280 DOI: 10.1063/1.4746988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A nuclear magnetic resonance apparatus for experiments in pulsed high magnetic fields is described. The magnetic field pulses created together with various magnet coils determine the requirements such an apparatus has to fulfill to be operated successfully in pulsed fields. Independent of the chosen coil it is desirable to operate the entire experiment at the highest possible bandwidth such that a correspondingly large temporal fraction of the magnetic field pulse can be used to probe a given sample. Our apparatus offers a bandwidth of up to 20 MHz and has been tested successfully at the Hochfeld-Magnetlabor Dresden, even in a very fast dual coil magnet that has produced a peak field of 94.2 T. Using a medium-sized single coil with a significantly slower dependence, it is possible to perform advanced multi-pulse nuclear magnetic resonance experiments. As an example we discuss a Carr-Purcell spin echo sequence at a field of 62 T.
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Affiliation(s)
- Benno Meier
- University of Leipzig, Faculty of Physics and Earth Science, Linnéstrasse 5, 04103 Leipzig, Germany.
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Kozuki K, Nagashima T, Hangyo M. Measurement of electron paramagnetic resonance using terahertz time-domain spectroscopy. OPTICS EXPRESS 2011; 19:24950-24956. [PMID: 22273888 DOI: 10.1364/oe.19.024950] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present a frequency-domain electron spin resonance (ESR) measurement system using terahertz time-domain spectroscopy. A crossed polarizer technique is utilized to increase the sensitivity in detecting weak ESR signals of paramagnets caused by magnetic dipole transitions between magnetic sublevels. We demonstrate the measurements of ESR signal of paramagnetic copper(II) sulfate pentahydrate with uniaxial anisotropy of the g-factor under magnetic fields up to 10 T. The lineshape of the obtained ESR signals agrees well with the theoretical predictions for a powder sample with the uniaxial anisotropy.
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Affiliation(s)
- Kohei Kozuki
- Institute of Laser Engineering, Osaka University, Suita, Osaka, Japan
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Bhattacharyya J, Wagner M, Zybell S, Winnerl S, Stehr D, Helm M, Schneider H. Simultaneous time and wavelength resolved spectroscopy under two-colour near infrared and terahertz excitation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:103107. [PMID: 22047280 DOI: 10.1063/1.3653394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Time and wavelength resolved spectroscopy requires optical sources emitting very short pulses and a fast detection mechanism capable of measuring the evolution of the output spectrum as a function of time. We use table-top Ti:sapphire lasers and a free-electron laser (FEL) emitting ps pulses as excitation sources and a streak camera coupled to a spectrometer for detection. One of the major aspects of this setup is the synchronization of pulses from the two lasers which we describe in detail. Optical properties of the FEL pulses are studied by autocorrelation and electro-optic sampling measurements. We discuss the advantages of using this setup to perform photoluminescence quenching in semiconductor quantum wells and quantum dots. Carrier redistribution due to pulsed excitation in these heterostructures can be investigated directly. Sideband generation in quantum wells is also studied where the intense FEL pulses facilitate the detection of the otherwise weak nonlinear effect.
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Affiliation(s)
- J Bhattacharyya
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany.
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Meier B, Greiser S, Haase J, Herrmannsdörfer T, Wolff-Fabris F, Wosnitza J. NMR signal averaging in 62T pulsed fields. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 210:1-6. [PMID: 21367630 DOI: 10.1016/j.jmr.2011.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 01/28/2011] [Accepted: 02/06/2011] [Indexed: 05/30/2023]
Abstract
Nuclear Magnetic Resonance (NMR) experiments in pulsed high magnetic fields up to 62T at the Dresden High Magnetic Field Laboratory (Hochfeld-Magnetlabor Dresden) are reported. The time dependence of the magnetic field is investigated by observing various free induction decays (FIDs) in the vicinity of the maximum of the field pulse. By analyzing each FID's phase and its evolution with time the magnetic field's time dependence can be determined with high precision. Assuming a quadratic or cubic dependence on time near the field maximum its confidence is found to be better than ± 0.03ppm at low fields and ± 0.8ppm near 62T. In turn, the thus obtained time dependence of the field can be used to demodulate and phase-correct all FIDs so that they appear phase-locked to each other. As a consequence signal averaging is possible. The increase in signal-to-noise ratio is found to be close to that expected theoretically. This shows that the intrinsic time dependence of the pulsed fields can be removed so that the NMR signals appear to be taken at rather stable static field. This opens up the possibility of performing precise shift measurements and signal averaging also of unknown, weak signals if a reference signal is measured during the same field pulse with a double-resonance probe.
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Affiliation(s)
- Benno Meier
- University of Leipzig, Faculty of Physics and Earth Science, Linnéstrasse 5, 04103 Leipzig, Germany
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