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Kavai M, Friedman J, Sherman K, Gong M, Giannakis I, Hajinazar S, Hu H, Grefe SE, Leshen J, Yang Q, Nakatsuji S, Kolmogorov AN, Si Q, Lawler M, Aynajian P. Inhomogeneous Kondo-lattice in geometrically frustrated Pr 2Ir 2O 7. Nat Commun 2021; 12:1377. [PMID: 33654070 PMCID: PMC7925525 DOI: 10.1038/s41467-021-21698-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 02/07/2021] [Indexed: 11/15/2022] Open
Abstract
Magnetic fluctuations induced by geometric frustration of local Ir-spins disturb the formation of long-range magnetic order in the family of pyrochlore iridates. As a consequence, Pr2Ir2O7 lies at a tuning-free antiferromagnetic-to-paramagnetic quantum critical point and exhibits an array of complex phenomena including the Kondo effect, biquadratic band structure, and metallic spin liquid. Using spectroscopic imaging with the scanning tunneling microscope, complemented with machine learning, density functional theory and theoretical modeling, we probe the local electronic states in Pr2Ir2O7 and find an electronic phase separation. Nanoscale regions with a well-defined Kondo resonance are interweaved with a non-magnetic metallic phase with Kondo-destruction. These spatial nanoscale patterns display a fractal geometry with power-law behavior extended over two decades, consistent with being in proximity to a critical point. Our discovery reveals a nanoscale tuning route, viz. using a spatial variation of the electronic potential as a means of adjusting the balance between Kondo entanglement and geometric frustration. Pyrochlore iridates lie at a tuning-free magnetic quantum critical point hosting several complex exotic phenomena. Here, the authors discover an electronic phase separation in single crystalline Pr2Ir2O7, where well-defined Kondo resonances are interweaved with a non-magnetic metallic phase with Kondo-destruction.
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Affiliation(s)
- Mariam Kavai
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA
| | - Joel Friedman
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA
| | - Kyle Sherman
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA
| | - Mingda Gong
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA
| | - Ioannis Giannakis
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA
| | - Samad Hajinazar
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA
| | - Haoyu Hu
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Sarah E Grefe
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Justin Leshen
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA
| | - Qiu Yang
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba, Japan
| | - Satoru Nakatsuji
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba, Japan.,Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo, Japan.,Trans-scale Quantum Science Institute, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Aleksey N Kolmogorov
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA
| | - Qimiao Si
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Michael Lawler
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA
| | - Pegor Aynajian
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA.
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Evolution of the Kondo lattice electronic structure above the transport coherence temperature. Proc Natl Acad Sci U S A 2020; 117:23467-23476. [PMID: 32887802 DOI: 10.1073/pnas.2001778117] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The temperature-dependent evolution of the Kondo lattice is a long-standing topic of theoretical and experimental investigation and yet it lacks a truly microscopic description of the relation of the basic f-c hybridization processes to the fundamental temperature scales of Kondo screening and Fermi-liquid lattice coherence. Here, the temperature dependence of f-c hybridized band dispersions and Fermi-energy f spectral weight in the Kondo lattice system CeCoIn5 is investigated using f-resonant angle-resolved photoemission spectroscopy (ARPES) with sufficient detail to allow direct comparison to first-principles dynamical mean-field theory (DMFT) calculations containing full realism of crystalline electric-field states. The ARPES results, for two orthogonal (001) and (100) cleaved surfaces and three different f-c hybridization configurations, with additional microscopic insight provided by DMFT, reveal f participation in the Fermi surface at temperatures much higher than the lattice coherence temperature, [Formula: see text] K, commonly believed to be the onset for such behavior. The DMFT results show the role of crystalline electric-field (CEF) splittings in this behavior and a T-dependent CEF degeneracy crossover below [Formula: see text] is specifically highlighted. A recent ARPES report of low T Luttinger theorem failure for CeCoIn5 is shown to be unjustified by current ARPES data and is not found in the theory.
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Yue L, Xue S, Li J, Hu W, Barbour A, Zheng F, Wang L, Feng J, Wilkins SB, Mazzoli C, Comin R, Li Y. Distinction between pristine and disorder-perturbed charge density waves in ZrTe 3. Nat Commun 2020; 11:98. [PMID: 31911603 PMCID: PMC6946692 DOI: 10.1038/s41467-019-13813-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 11/29/2019] [Indexed: 11/09/2022] Open
Abstract
Charge density waves (CDWs) in the cuprate high-temperature superconductors have evoked much interest, yet their typical short-range nature has raised questions regarding the role of disorder. Here we report a resonant X-ray diffraction study of ZrTe[Formula: see text], a model CDW system, with focus on the influence of disorder. Near the CDW transition temperature, we observe two independent signals that arise concomitantly, only to become clearly separated in momentum while developing very different correlation lengths in the well-ordered state that is reached at a distinctly lower temperature. Anomalously slow dynamics of mesoscopic charge domains are further found near the transition temperature, in spite of the expected strong thermal fluctuations. Our observations signify the presence of distinct experimental fingerprints of pristine and disorder-perturbed CDWs. We discuss the latter also in the context of Friedel oscillations, which we argue might promote CDW formation via a self-amplifying process.
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Affiliation(s)
- Li Yue
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Shangjie Xue
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jiarui Li
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Wen Hu
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Andi Barbour
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Feipeng Zheng
- Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, 510632, China
| | - Lichen Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
| | - Ji Feng
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China
| | - Stuart B Wilkins
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Claudio Mazzoli
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Riccardo Comin
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Yuan Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China.
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Gyenis A, Feldman BE, Randeria MT, Peterson GA, Bauer ED, Aynajian P, Yazdani A. Visualizing heavy fermion confinement and Pauli-limited superconductivity in layered CeCoIn 5. Nat Commun 2018; 9:549. [PMID: 29416021 PMCID: PMC5803268 DOI: 10.1038/s41467-018-02841-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 01/03/2018] [Indexed: 11/09/2022] Open
Abstract
Layered material structures play a key role in enhancing electron–electron interactions to create correlated metallic phases that can transform into unconventional superconducting states. The quasi-two-dimensional electronic properties of such compounds are often inferred indirectly through examination of bulk properties. Here we use scanning tunneling microscopy to directly probe in cross-section the quasi-two-dimensional electronic states of the heavy fermion superconductor CeCoIn5. Our measurements reveal the strong confined nature of quasiparticles, anisotropy of tunneling characteristics, and layer-by-layer modulated behavior of the precursor pseudogap gap phase. In the interlayer coupled superconducting state, the orientation of line defects relative to the d-wave order parameter determines whether in-gap states form due to scattering. Spectroscopic imaging of the anisotropic magnetic vortex cores directly characterizes the short interlayer superconducting coherence length and shows an electronic phase separation near the upper critical in-plane magnetic field, consistent with a Pauli-limited first-order phase transition into a pseudogap phase. The electronic properties along the out-of-plane direction of layered materials are often inferred indirectly. Here, Gyenis et al. directly probe in cross-section the quasi-two-dimensional correlated electronic states of the heavy fermion superconductor CeCoIn5.
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Affiliation(s)
- András Gyenis
- Joseph Henry Laboratories of Physics, Department of Physics, Princeton University, Princeton, NJ, 08544, USA.,Department of Electrical Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Benjamin E Feldman
- Joseph Henry Laboratories of Physics, Department of Physics, Princeton University, Princeton, NJ, 08544, USA.,Department of Physics, Stanford University, Stanford, CA, 94305, USA
| | - Mallika T Randeria
- Joseph Henry Laboratories of Physics, Department of Physics, Princeton University, Princeton, NJ, 08544, USA
| | - Gabriel A Peterson
- Joseph Henry Laboratories of Physics, Department of Physics, Princeton University, Princeton, NJ, 08544, USA.,National Institute of Standards and Technology, Boulder, CO, 80305, USA
| | - Eric D Bauer
- Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Pegor Aynajian
- Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, 13902, USA
| | - Ali Yazdani
- Joseph Henry Laboratories of Physics, Department of Physics, Princeton University, Princeton, NJ, 08544, USA.
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