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Luo T, Ilyas B, Hoegen AV, Lee Y, Park J, Park JG, Gedik N. Time-of-flight detection of terahertz phonon-polariton. Nat Commun 2024; 15:2276. [PMID: 38480696 PMCID: PMC10937925 DOI: 10.1038/s41467-024-46515-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 02/16/2024] [Indexed: 03/17/2024] Open
Abstract
A polariton is a fundamental quasiparticle that arises from strong light-matter interaction and as such has attracted wide scientific and practical interest. When light is strongly coupled to the crystal lattice, it gives rise to phonon-polaritons (PPs), which have been proven useful in the dynamical manipulation of quantum materials and the advancement of terahertz technologies. Yet, current detection and characterization methods of polaritons are still limited. Traditional techniques such as Raman or transient grating either rely on fine-tuning of external parameters or complex phase extraction techniques. To overcome these inherent limitations, we propose and demonstrate a technique based on a time-of-flight measurement of PPs. We resonantly launch broadband PPs with intense terahertz fields and measure the time-of-flight of each spectral component with time-resolved second harmonic generation. The time-of-flight information, combined with the PP attenuation, enables us to resolve the real and imaginary parts of the PP dispersion relation. We demonstrate this technique in the van der Waals magnets NiI2 and MnPS3 and reveal a hidden magnon-phonon interaction. We believe that this approach will unlock new opportunities for studying polaritons across diverse material systems and enhance our understanding of strong light-matter interaction.
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Affiliation(s)
- Tianchuang Luo
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Batyr Ilyas
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - A von Hoegen
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Youjin Lee
- Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
| | - Jaena Park
- Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
| | - Je-Geun Park
- Department of Physics and Astronomy, Seoul National University, Seoul, South Korea
| | - Nuh Gedik
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA.
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Fechner M, Först M, Orenstein G, Krapivin V, Disa AS, Buzzi M, von Hoegen A, de la Pena G, Nguyen QL, Mankowsky R, Sander M, Lemke H, Deng Y, Trigo M, Cavalleri A. Quenched lattice fluctuations in optically driven SrTiO 3. Nat Mater 2024; 23:363-368. [PMID: 38302742 PMCID: PMC10917662 DOI: 10.1038/s41563-023-01791-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 12/14/2023] [Indexed: 02/03/2024]
Abstract
Crystal lattice fluctuations, which are known to influence phase transitions of quantum materials in equilibrium, are also expected to determine the dynamics of light-induced phase changes. However, they have only rarely been explored in these dynamical settings. Here we study the time evolution of lattice fluctuations in the quantum paraelectric SrTiO3, in which mid-infrared drives have been shown to induce a metastable ferroelectric state. Crucial in these physics is the competition between polar instabilities and antiferrodistortive rotations, which in equilibrium frustrate the formation of long-range ferroelectricity. We make use of high-intensity mid-infrared optical pulses to resonantly drive the Ti-O-stretching mode at 17 THz, and we measure the resulting change in lattice fluctuations using time-resolved X-ray diffuse scattering at a free-electron laser. After a prompt increase, we observe a long-lived quench in R-point antiferrodistortive lattice fluctuations. Their enhancement and reduction are theoretically explained by considering the fourth-order nonlinear phononic interactions to the driven optical phonon and third-order coupling to lattice strain, respectively. These observations provide a number of testable hypotheses for the physics of light-induced ferroelectricity.
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Affiliation(s)
- M Fechner
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
| | - M Först
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
| | - G Orenstein
- Stanford Pulse Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - V Krapivin
- Stanford Pulse Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - A S Disa
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
- School of Applied & Engineering Physics, Cornell University, Ithaca, NY, USA
| | - M Buzzi
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - A von Hoegen
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - G de la Pena
- Stanford Pulse Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Q L Nguyen
- Stanford Pulse Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - R Mankowsky
- Paul Scherrer Institut, Villigen, Switzerland
| | - M Sander
- Paul Scherrer Institut, Villigen, Switzerland
| | - H Lemke
- Paul Scherrer Institut, Villigen, Switzerland
| | - Y Deng
- Paul Scherrer Institut, Villigen, Switzerland
| | - M Trigo
- Stanford Pulse Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - A Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, UK.
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Disa AS, Curtis J, Fechner M, Liu A, von Hoegen A, Först M, Nova TF, Narang P, Maljuk A, Boris AV, Keimer B, Cavalleri A. Photo-induced high-temperature ferromagnetism in YTiO 3. Nature 2023; 617:73-78. [PMID: 37138109 PMCID: PMC10156606 DOI: 10.1038/s41586-023-05853-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 02/16/2023] [Indexed: 05/05/2023]
Abstract
In quantum materials, degeneracies and frustrated interactions can have a profound impact on the emergence of long-range order, often driving strong fluctuations that suppress functionally relevant electronic or magnetic phases1-7. Engineering the atomic structure in the bulk or at heterointerfaces has been an important research strategy to lift these degeneracies, but these equilibrium methods are limited by thermodynamic, elastic and chemical constraints8. Here we show that all-optical, mode-selective manipulation of the crystal lattice can be used to enhance and stabilize high-temperature ferromagnetism in YTiO3, a material that shows only partial orbital polarization, an unsaturated low-temperature magnetic moment and a suppressed Curie temperature, Tc = 27 K (refs. 9-13). The enhancement is largest when exciting a 9 THz oxygen rotation mode, for which complete magnetic saturation is achieved at low temperatures and transient ferromagnetism is realized up to Tneq > 80 K, nearly three times the thermodynamic transition temperature. We interpret these effects as a consequence of the light-induced dynamical changes to the quasi-degenerate Ti t2g orbitals, which affect the magnetic phase competition and fluctuations found in the equilibrium state14-20. Notably, the light-induced high-temperature ferromagnetism discovered in our work is metastable over many nanoseconds, underscoring the ability to dynamically engineer practically useful non-equilibrium functionalities.
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Affiliation(s)
- A S Disa
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA.
| | - J Curtis
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- College of Letters and Science, University of California, Los Angeles, CA, USA
| | - M Fechner
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - A Liu
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - A von Hoegen
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - M Först
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - T F Nova
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
| | - P Narang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- College of Letters and Science, University of California, Los Angeles, CA, USA
| | - A Maljuk
- Leibniz Institute for Solid State and Materials Research Dresden, Dresden, Germany
| | - A V Boris
- Max Planck Institute for Solid State Research, Stuttgart, Germany
| | - B Keimer
- Max Planck Institute for Solid State Research, Stuttgart, Germany
| | - A Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany.
- Clarendon Laboratory, Department of Physics, Oxford University, Oxford, UK.
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von Hoegen A, Mankowsky R, Fechner M, Först M, Cavalleri A. Probing the interatomic potential of solids with strong-field nonlinear phononics. Nature 2018; 555:79-82. [PMID: 29466328 DOI: 10.1038/nature25484] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 12/04/2017] [Indexed: 01/24/2023]
Abstract
Nonlinear optical techniques at visible frequencies have long been applied to condensed matter spectroscopy. However, because many important excitations of solids are found at low energies, much can be gained from the extension of nonlinear optics to mid-infrared and terahertz frequencies. For example, the nonlinear excitation of lattice vibrations has enabled the dynamic control of material functions. So far it has only been possible to exploit second-order phonon nonlinearities at terahertz field strengths near one million volts per centimetre. Here we achieve an order-of-magnitude increase in field strength and explore higher-order phonon nonlinearities. We excite up to five harmonics of the A1 (transverse optical) phonon mode in the ferroelectric material lithium niobate. By using ultrashort mid-infrared laser pulses to drive the atoms far from their equilibrium positions, and measuring the large-amplitude atomic trajectories, we can sample the interatomic potential of lithium niobate, providing a benchmark for ab initio calculations for the material. Tomography of the energy surface by high-order nonlinear phononics could benefit many aspects of materials research, including the study of classical and quantum phase transitions.
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Affiliation(s)
- A von Hoegen
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - R Mankowsky
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - M Fechner
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - M Först
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - A Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany.,Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU, UK
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Mankowsky R, Fechner M, Först M, von Hoegen A, Porras J, Loew T, Dakovski GL, Seaberg M, Möller S, Coslovich G, Keimer B, Dhesi SS, Cavalleri A. Optically induced lattice deformations, electronic structure changes, and enhanced superconductivity in YBa 2Cu 3O 6.48. Struct Dyn 2017; 4:044007. [PMID: 28345009 PMCID: PMC5336478 DOI: 10.1063/1.4977672] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 02/16/2017] [Indexed: 05/23/2023]
Abstract
Resonant optical excitation of apical oxygen vibrational modes in the normal state of underdoped YBa2Cu3O6+x induces a transient state with optical properties similar to those of the equilibrium superconducting state. Amongst these, a divergent imaginary conductivity and a plasma edge are transiently observed in the photo-stimulated state. Femtosecond hard x-ray diffraction experiments have been used in the past to identify the transient crystal structure in this non-equilibrium state. Here, we start from these crystallographic features and theoretically predict the corresponding electronic rearrangements that accompany these structural deformations. Using density functional theory, we predict enhanced hole-doping of the CuO2 planes. The empty chain Cu dy2-z2 orbital is calculated to strongly reduce in energy, which would increase c-axis transport and potentially enhance the interlayer Josephson coupling as observed in the THz-frequency response. From these results, we calculate changes in the soft x-ray absorption spectra at the Cu L-edge. Femtosecond x-ray pulses from a free electron laser are used to probe changes in absorption at two photon energies along this spectrum and provide data consistent with these predictions.
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Affiliation(s)
- R Mankowsky
- Max Planck Institute for the Structure and Dynamics of Matter , Hamburg, Germany
| | - M Fechner
- Max Planck Institute for the Structure and Dynamics of Matter , Hamburg, Germany
| | - M Först
- Max Planck Institute for the Structure and Dynamics of Matter , Hamburg, Germany
| | - A von Hoegen
- Max Planck Institute for the Structure and Dynamics of Matter , Hamburg, Germany
| | - J Porras
- Max Planck Institute for Solid State Research , Stuttgart, Germany
| | - T Loew
- Max Planck Institute for Solid State Research , Stuttgart, Germany
| | - G L Dakovski
- Linac Coherent Light Source, Stanford Linear Accelerator Center (SLAC) National Accelerator Laboratory , Menlo Park, California 94025, USA
| | - M Seaberg
- Linac Coherent Light Source, Stanford Linear Accelerator Center (SLAC) National Accelerator Laboratory , Menlo Park, California 94025, USA
| | - S Möller
- Linac Coherent Light Source, Stanford Linear Accelerator Center (SLAC) National Accelerator Laboratory , Menlo Park, California 94025, USA
| | - G Coslovich
- Linac Coherent Light Source, Stanford Linear Accelerator Center (SLAC) National Accelerator Laboratory , Menlo Park, California 94025, USA
| | - B Keimer
- Max Planck Institute for Solid State Research , Stuttgart, Germany
| | - S S Dhesi
- Diamond Light Source, Harwell Science and Innovation Campus , Didcot OX11 0DE, United Kingdom
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Abstract
We report on the demonstration of ultrafast optical reversal of the ferroelectric polarization in LiNbO_{3}. Rather than driving the ferroelectric mode directly, we couple to it indirectly by resonant excitation of an auxiliary high-frequency phonon mode with femtosecond midinfrared pulses. Because of strong anharmonic coupling between these modes, the atoms are directionally displaced along the ferroelectric mode and the polarization is transiently reversed, as revealed by time-resolved, phase-sensitive, second-harmonic generation. This reversal can be induced in both directions, a key prerequisite for practical applications.
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Affiliation(s)
- R Mankowsky
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - A von Hoegen
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - M Först
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - A Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
- Department of Physics, University of Oxford, Clarendon Laboratory, Oxford OX1 3PU, United Kingdom
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von Hoegen A. [Tuberculin- research progress- methods-costs results-questions]. Offentl Gesundheitswes 1977; 39:122-7. [PMID: 140343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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von Hoegen A. [Establishment and work of a modern tuberculosis community health service]. Offentl Gesundheitswes 1971; 33:Suppl 2:49-57. [PMID: 4253608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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