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Sobirey L, Biss H, Luick N, Bohlen M, Moritz H, Lompe T. Observing the Influence of Reduced Dimensionality on Fermionic Superfluids. PHYSICAL REVIEW LETTERS 2022; 129:083601. [PMID: 36053698 DOI: 10.1103/physrevlett.129.083601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Understanding the origins of unconventional superconductivity has been a major focus of condensed matter physics for many decades. While many questions remain unanswered, experiments have found the highest critical temperatures in layered two-dimensional materials. However, to what extent the remarkable stability of these strongly correlated 2D superfluids is affected by their reduced dimensionality is still an open question. Here, we use dilute gases of ultracold fermionic atoms as a model system to directly observe the influence of dimensionality on the stability of strongly interacting fermionic superfluids. We find that the superfluid gap follows the same universal function of the interaction strength regardless of dimensionality, which suggests that there is no inherent difference in the stability of two- and three-dimensional fermionic superfluids. Finally, we compare our data to results from solid state systems and find a similar relation between the interaction strength and the gap for a wide range of two- and three-dimensional superconductors.
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Affiliation(s)
- Lennart Sobirey
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Hauke Biss
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
| | - Niclas Luick
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
| | - Markus Bohlen
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
| | - Henning Moritz
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
| | - Thomas Lompe
- Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg
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2
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Chen SD, Hashimoto M, He Y, Song D, He JF, Li YF, Ishida S, Eisaki H, Zaanen J, Devereaux TP, Lee DH, Lu DH, Shen ZX. Unconventional spectral signature of T c in a pure d-wave superconductor. Nature 2022; 601:562-567. [PMID: 35082417 DOI: 10.1038/s41586-021-04251-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/13/2021] [Indexed: 11/09/2022]
Abstract
In conventional superconductors, the phase transition into a zero-resistance and perfectly diamagnetic state is accompanied by a jump in the specific heat and the opening of a spectral gap1. In the high-transition-temperature (high-Tc) cuprates, although the transport, magnetic and thermodynamic signatures of Tc have been known since the 1980s2, the spectroscopic singularity associated with the transition remains unknown. Here we resolve this long-standing puzzle with a high-precision angle-resolved photoemission spectroscopy (ARPES) study on overdoped (Bi,Pb)2Sr2CaCu2O8+δ (Bi2212). We first probe the momentum-resolved electronic specific heat via spectroscopy and reproduce the specific heat peak at Tc, completing the missing link for a holistic description of superconductivity. Then, by studying the full momentum, energy and temperature evolution of the spectra, we reveal that this thermodynamic anomaly arises from the singular growth of in-gap spectral intensity across Tc. Furthermore, we observe that the temperature evolution of in-gap intensity is highly anisotropic in the momentum space, and the gap itself obeys both the d-wave functional form and particle-hole symmetry. These findings support the scenario that the superconducting transition is driven by phase fluctuations. They also serve as an anchor point for understanding the Fermi arc and pseudogap phenomena in underdoped cuprates.
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Affiliation(s)
- Su-Di Chen
- Department of Applied Physics, Stanford University, Stanford, CA, USA.,Department of Physics, Stanford University, Stanford, CA, USA.,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.,Kavli Energy NanoScience Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Makoto Hashimoto
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Yu He
- Department of Applied Physics, Stanford University, Stanford, CA, USA.,Department of Physics, Stanford University, Stanford, CA, USA.,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.,Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Dongjoon Song
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan.,Center for Correlated Electron Systems, Institute for Basic Science, Seoul, Republic of Korea
| | - Jun-Feng He
- Department of Applied Physics, Stanford University, Stanford, CA, USA.,Department of Physics, Stanford University, Stanford, CA, USA.,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.,Department of Physics, University of Science and Technology of China, Hefei, China
| | - Ying-Fei Li
- Department of Applied Physics, Stanford University, Stanford, CA, USA.,Department of Physics, Stanford University, Stanford, CA, USA.,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA
| | - Shigeyuki Ishida
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Hiroshi Eisaki
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Jan Zaanen
- Institute Lorentz for Theoretical Physics, Leiden University, Leiden, The Netherlands
| | - Thomas P Devereaux
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.,Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Dung-Hai Lee
- Department of Physics, University of California, Berkeley, Berkeley, CA, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Dong-Hui Lu
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Zhi-Xun Shen
- Department of Applied Physics, Stanford University, Stanford, CA, USA. .,Department of Physics, Stanford University, Stanford, CA, USA. .,Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University, Menlo Park, CA, USA.
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3
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Aftabi A, Mozaffari M. Fluctuation induced conductivity and pseudogap state studies of Bi 1.6Pb 0.4Sr 2Ca 2Cu 3O 10+δ superconductor added with ZnO nanoparticles. Sci Rep 2021; 11:4341. [PMID: 33619318 PMCID: PMC7900248 DOI: 10.1038/s41598-021-83218-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 02/01/2021] [Indexed: 01/31/2023] Open
Abstract
The major limitations of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductor are weak flux pinning capability and weak inter-grains coupling that lead to a low critical current density and low critical magnetic field which impedes the suppleness of this material towards practical applications. The addition of nanoscales impurities can create artificial pining centers that may improve flux pinning capability and intergranular coupling. In this work, the influences of ZnO nanoparticles on the superconducting parameters and pseudogap properties of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductor are investigated using fluctuation induced conductivity analyses. Results demonstrate that the ZnO nanoparticles addition improves the formation of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ phase significantly. Various superconducting parameters include coherence length along c-axis (ξc(0)), penetration depth (λpd(0)), Fermi velocity (vF), Fermi energy (EF), lower and upper critical magnetic fields (Bc1(0) and Bc2(0) respectively) and critical current density (Jc(0)), are estimated for samples with different amounts of ZnO nanoparticles. It is found that the values of the Bc1(0), Bc2(0), and Jc(0) are improved significantly in the 0.2 wt% ZnO added sample in comparison to the ZnO-free sample. The magnitude and temperature dependence of the pseudogap Δ*(T) is calculated using the local pairs model. The obtained values of Tpair, the temperature at which local pairs are transformed from strongly coupled bosons into the fluctuating Cooper pairs, increases as the added ZnO nanoparticles concentration enhances up to 0.2 wt%. Also, the estimated values for the superconducting gap at T = 0 K (Δ(0)) are decreased from about 26 meV in ZnO-free sample to about 22 meV in 0.2 wt% ZnO added sample and then increases for higher values of additive.
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Affiliation(s)
- Ali Aftabi
- grid.411189.40000 0000 9352 9878Department of Physics, Faculty of Science, University of Kurdistan, 66177-15175 Sanandaj, Iran
| | - Morteza Mozaffari
- grid.411750.60000 0001 0454 365XDepartment of Physics, Faculty of Physics, University of Isfahan, 81746-73441 Isfahan, Iran
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Solovjov AL, Omelchenko LV, Petrenko EV, Vovk RV, Khotkevych VV, Chroneos A. Peculiarities of pseudogap in Y 0.95Pr 0.05Ba 2Cu 3O 7-δ single crystals under pressure up to 1.7 GPa. Sci Rep 2019; 9:20424. [PMID: 31892715 PMCID: PMC6938474 DOI: 10.1038/s41598-019-55959-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/30/2019] [Indexed: 11/09/2022] Open
Abstract
The effect of hydrostatic pressure up to P = 1.7 GPa on the fluctuation conductivity σ'(T) and pseudogap ∆*(T) in Y0.95Pr0.05Ba2Cu3O7-δ single crystal with critical temperature Тс = 85.2 K (at P = 0) was investigated. The application of pressure leads to the increase in Tc with dTc/dP = +1.82 K∙GPa-1 while the resistance decreases as dlnρ(100 K)/dP = -(10.5 ± 0.2) %∙GPa-1. Regardless of the pressure, in the temperature interval from Tc to T0 (~88 K at P = 0) the behaviour of σ'(T) is well described by the Aslamazov - Larkin (AL - 3D) fluctuation theory, and above the T0 by the Lawrence - Doniach theory (LD). The Maki-Thompson (MT - 2D) fluctuation contribution is not observed. This indicates the presence of structural defects in the sample induced by Pr. Here it is determined for the first time that when the pressure is applied to the Y1-xPrxBa2Cu3O7-δ single crystal, the pseudogap increases as dlnΔ*/dP = 0.17 GPa-1.
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Affiliation(s)
- A L Solovjov
- B. Verkin Institute for Low Temperature Physics and Engineering, NAN of Ukraine, 47 Nauky Avenue, Kharkiv, 61103, Ukraine
| | - L V Omelchenko
- B. Verkin Institute for Low Temperature Physics and Engineering, NAN of Ukraine, 47 Nauky Avenue, Kharkiv, 61103, Ukraine
| | - E V Petrenko
- B. Verkin Institute for Low Temperature Physics and Engineering, NAN of Ukraine, 47 Nauky Avenue, Kharkiv, 61103, Ukraine
| | - R V Vovk
- V. Karazin Kharkiv National University, 4 Svobody Square, Kharkiv, 61077, Ukraine
| | - V V Khotkevych
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, OX11 0DE, United Kingdom
| | - A Chroneos
- Department of Materials, Imperial College, London, SW7 2AZ, UK.
- Faculty of Engineering, Environment and Computing, Coventry University, Priory Street, Coventry, CV1 5FB, United Kingdom.
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5
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Solovjov AL, Petrenko EV, Omelchenko LV, Vovk RV, Goulatis IL, Chroneos A. Effect of annealing on a pseudogap state in untwinned YBa 2Cu 3O 7-δ single crystals. Sci Rep 2019; 9:9274. [PMID: 31239510 PMCID: PMC6592912 DOI: 10.1038/s41598-019-45286-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 05/21/2019] [Indexed: 11/21/2022] Open
Abstract
The effect of annealing both in the oxygen atmosphere and at room temperatures on physical properties such as the pseudogap (Δ*(T)) and excess conductivity (σ'(T)) of untwined YBa2Cu3O7-δ (YBCO) single crystal with a small deviation from oxygen stoichiometry is studied. It was revealed that as the charge carrier density, nf, increases, Тс also slightly increases, whereas the temperature of the pseudogap opening, T*, decreases noticeably, which is consistent with the phase diagram (PD) of cuprates. The excess conductivity in the vicinity of Tc is represented by the Aslamazov-Larkin and Hikami-Larkin fluctuation theories, illustrating the three-dimensional to two-dimensional (i.e. 3D-2D) crossover with an increase in temperature. The crossover temperature T0 determines the coherence length along the c axis is ξc(0) = 0.86 Å, that is 2.6 times larger than for optimally doped YBCO single crystals with defects. Taking into account the short coherence length in high-temperature superconductors, in the model of free charge carriers the phase relaxation time of fluctuating Cooper pairs is determined, τφ (100 K) = (4.55 ± 0.4) · 10-13 s, which is slightly (1.2 times) larger than in well-structured YBCO films, and as in films, does not depend on nf. It is shown that Δ*(T) at different annealing stages practically does not change its shape. As in the well-structured YBCO films, Δ*(T) demonstrates maximum at Tpair~124 K which depends weakly on nf. However, the maximum value of Δ*(Tpair) increases with increasing nf, as it follows from the PD of cuprates. Comparing the experimental data with the Peters-Bauer theory we estimated the density of local pairs ≈ 0.3 near Tc that is a common value for high-temperature superconductors.
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Affiliation(s)
- A L Solovjov
- B. I. Verkin Institute for Low Temperature Physics and Engineering of National Academy of Science of Ukraine, 47 Nauki ave., 61103, Kharkov, Ukraine
| | - E V Petrenko
- B. I. Verkin Institute for Low Temperature Physics and Engineering of National Academy of Science of Ukraine, 47 Nauki ave., 61103, Kharkov, Ukraine
| | - L V Omelchenko
- B. I. Verkin Institute for Low Temperature Physics and Engineering of National Academy of Science of Ukraine, 47 Nauki ave., 61103, Kharkov, Ukraine
| | - R V Vovk
- Physics Department, V. Karazin Kharkiv National University, Svobody Sq. 4, 61077, Kharkiv, Ukraine
| | - I L Goulatis
- Physics Department, V. Karazin Kharkiv National University, Svobody Sq. 4, 61077, Kharkiv, Ukraine
| | - A Chroneos
- Department of Materials, Imperial College, London, SW7 2AZ, UK.
- Faculty of Engineering, Environment and Computing, Coventry University, Priory Street, Coventry, CV1 5FB, United Kingdom.
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6
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He Y, Hashimoto M, Song D, Chen SD, He J, Vishik IM, Moritz B, Lee DH, Nagaosa N, Zaanen J, Devereaux TP, Yoshida Y, Eisaki H, Lu DH, Shen ZX. Rapid change of superconductivity and electron-phonon coupling through critical doping in Bi-2212. Science 2018; 362:62-65. [DOI: 10.1126/science.aar3394] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 07/30/2018] [Indexed: 11/02/2022]
Affiliation(s)
- Y. He
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - M. Hashimoto
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - D. Song
- National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan
| | - S.-D. Chen
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - J. He
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - I. M. Vishik
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - B. Moritz
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - D.-H. Lee
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - N. Nagaosa
- Quantum-Phase Electronics Center, Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - J. Zaanen
- Instituut-Lorentz for Theoretical Physics, Leiden University, Leiden, Netherlands
| | - T. P. Devereaux
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Y. Yoshida
- National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan
| | - H. Eisaki
- National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, Japan
| | - D. H. Lu
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Z.-X. Shen
- Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
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7
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Vishik IM. Photoemission perspective on pseudogap, superconducting fluctuations, and charge order in cuprates: a review of recent progress. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:062501. [PMID: 29595144 DOI: 10.1088/1361-6633/aaba96] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In the course of seeking the microscopic mechanism of superconductivity in cuprate high temperature superconductors, the pseudogap phase- the very abnormal 'normal' state on the hole-doped side- has proven to be as big of a quandary as superconductivity itself. Angle-resolved photoemission spectroscopy (ARPES) is a powerful tool for assessing the momentum-dependent phenomenology of the pseudogap, and recent technological developments have permitted a more detailed understanding. This report reviews recent progress in understanding the relationship between superconductivity and the pseudogap, the Fermi arc phenomena, and the relationship between charge order and pseudogap from the perspective of ARPES measurements.
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Affiliation(s)
- I M Vishik
- University of California, Davis, CA 95616, United States of America
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8
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Hussey NE, Buhot J, Licciardello S. A tale of two metals: contrasting criticalities in the pnictides and hole-doped cuprates. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:052501. [PMID: 29353812 DOI: 10.1088/1361-6633/aaa97c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The iron-based high temperature superconductors share a number of similarities with their copper-based counterparts, such as reduced dimensionality, proximity to states of competing order, and a critical role for 3d electron orbitals. Their respective temperature-doping phase diagrams also contain certain commonalities that have led to claims that the metallic and superconducting (SC) properties of both families are governed by their proximity to a quantum critical point (QCP) located inside the SC dome. In this review, we critically examine these claims and highlight significant differences in the bulk physical properties of both systems. While there is now a large body of evidence supporting the presence of a (magnetic) QCP in the iron pnictides, the situation in the cuprates is much less apparent, at least for the end point of the pseudogap phase. We argue that the opening of the normal state pseudogap in cuprates, so often tied to a putative QCP, arises from a momentum-dependent breakdown of quasiparticle coherence that sets in at much higher doping levels but which is driven by the proximity to the Mott insulating state at half filling. Finally, we present a new scenario for the cuprates in which this loss of quasiparticle integrity and its evolution with momentum, temperature and doping plays a key role in shaping the resultant phase diagram.
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Affiliation(s)
- N E Hussey
- High Field Magnet Laboratory (HFML-EMFL), Institute for Molecules and Materials, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, Netherlands
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9
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Ekino T, Gabovich AM, Suan Li M, Szymczak H, Voitenko AI. Quasiparticle conductance-voltage characteristics for break junctions involving d-wave superconductors: charge-density-wave effects. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:505602. [PMID: 29105650 DOI: 10.1088/1361-648x/aa9867] [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
Quasiparticle tunnel conductance-voltage characteristics (CVCs), [Formula: see text], were calculated for break junctions (BJs) made up of layered d-wave superconductors partially gapped by charge-density waves (CDWs). The current is assumed to flow in the ab-plane of electrodes. The influence of CDWs is analyzed by comparing the resulting CVCs with CVCs calculated for BJs made up of pure d-wave superconductors with relevant parameters. The main CDW-effects were found to be the appearance of new CVC peculiarities and the loss of CVC symmetry with respect to the V-sign. Tunnel directionality was shown to be one of the key factors in the formation of [Formula: see text] dependences. In particular, the orientation of electrodes with respect to the current channel becomes very important. As a result, [Formula: see text] can acquire a large variety of forms similar to those for tunnel junctions between superconductors with s-wave, d-wave, and mixed symmetry of their order parameters. The diversity of peculiarities is especially striking at finite temperatures. In the case of BJs made up of pure d-wave superconductors, the resulting CVC can include a two-peak gap-driven structure. The results were compared with the experimental BJ data for a number of high-T c oxides. It was shown that the large variety of the observed current-voltage characteristics can be interpreted in the framework of our approach. Thus, quasiparticle tunnel currents in the ab-plane can be used as an additional mean to detect CDWs competing with superconductivity in cuprates or other layered superconductors.
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Affiliation(s)
- T Ekino
- Hiroshima University, Graduate School of Integrated Arts and Sciences, Higashi-Hiroshima, 739-8521, Japan
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10
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Kondo T, Malaeb W, Ishida Y, Sasagawa T, Sakamoto H, Takeuchi T, Tohyama T, Shin S. Point nodes persisting far beyond Tc in Bi2212. Nat Commun 2015; 6:7699. [PMID: 26158431 PMCID: PMC4510699 DOI: 10.1038/ncomms8699] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 06/01/2015] [Indexed: 11/26/2022] Open
Abstract
In contrast to a complex feature of antinodal state, suffering from competing orders, the pairing gap of cuprates is obtained in the nodal region, which therefore holds the key to the superconducting mechanism. One of the biggest question is whether the point nodal state as a hallmark of d-wave pairing collapses at Tc like the BCS-type superconductors, or it instead survives above Tc turning into the preformed pair state. A difficulty in this issue comes from the small magnitude of the nodal gap, which has been preventing experimentalists from solving it. Here we use a laser ARPES capable of ultrahigh-energy resolution, and detect the point nodes surviving far beyond Tc in Bi2212. By tracking the temperature evolution of spectra, we reveal that the superconductivity occurs when the pair-breaking rate is suppressed smaller than the single-particle scattering rate on cooling, which governs the value of Tc in cuprates. The pairing gap of the high-Tc cuprates has been expected to close at the transition temperature, similarly to the case of conventional superconductors. Here the authors perform ARPES measurements on Bi2212, and reveal a point nodal gap formation beyond Tc, characterized in terms of three parameters.
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Affiliation(s)
- Takeshi Kondo
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - W Malaeb
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Y Ishida
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - T Sasagawa
- Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
| | - H Sakamoto
- Department of Crystalline Materials Science, Nagoya University, Nagoya 464-8603, Japan
| | - Tsunehiro Takeuchi
- Energy Materials Laboratory, Toyota Technological Institute, Nagoya 468-8511, Japan
| | - T Tohyama
- Department of Applied Physics, Tokyo University of Science, Tokyo 125-8585, Japan
| | - S Shin
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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11
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Allais A, Chowdhury D, Sachdev S. Connecting high-field quantum oscillations to zero-field electron spectral functions in the underdoped cuprates. Nat Commun 2014; 5:5771. [PMID: 25493606 DOI: 10.1038/ncomms6771] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 11/06/2014] [Indexed: 11/09/2022] Open
Abstract
The nature of the pseudogap regime of cuprate superconductors at low hole density remains unresolved. It has a number of seemingly distinct experimental signatures: a suppression of the paramagnetic spin susceptibility at high temperatures, low-energy electronic excitations that extend over arcs in the Brillouin zone, X-ray detection of charge-density wave order at intermediate temperatures and quantum oscillations at high magnetic fields and low temperatures. Here we show that a model of competing charge-density wave and superconducting orders provides a unified description of the intermediate and low-temperature regimes. We treat quantum oscillations at high field beyond semiclassical approximations, and find clear and robust signatures of an electron pocket compatible with existing observations; we also predict oscillations due to additional hole pockets. In the zero-field and intermediate temperature regime, we compute the electronic spectrum in the presence of thermally fluctuating charge-density and superconducting orders. Our results are compatible with experimental trends.
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Affiliation(s)
- Andrea Allais
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Debanjan Chowdhury
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Subir Sachdev
- Perimeter Institute for Theoretical Physics, Waterloo, Ontario, Canada N2L 2Y5
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12
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Chan MK, Veit MJ, Dorow CJ, Ge Y, Li Y, Tabis W, Tang Y, Zhao X, Barišić N, Greven M. In-plane magnetoresistance obeys Kohler's rule in the pseudogap phase of cuprate superconductors. PHYSICAL REVIEW LETTERS 2014; 113:177005. [PMID: 25379934 DOI: 10.1103/physrevlett.113.177005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Indexed: 06/04/2023]
Abstract
We report in-plane resistivity (ρ) and transverse magnetoresistance (MR) measurements for underdoped HgBa(2)CuO(4+δ) (Hg1201). Contrary to the long-standing view that Kohler's rule is strongly violated in underdoped cuprates, we find that it is in fact satisfied in the pseudogap phase of Hg1201. The transverse MR shows a quadratic field dependence, δρ/ρ(0)=aH(2), with a(T)∝T(-4). In combination with the observed ρ∝T(2) dependence, this is consistent with a single Fermi-liquid quasiparticle scattering rate. We show that this behavior is typically masked in cuprates with lower structural symmetry or strong disorder effects.
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Affiliation(s)
- M K Chan
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - M J Veit
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - C J Dorow
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Y Ge
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Y Li
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - W Tabis
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA and AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Al. A. Mickiewicza 30, 30-059 Krakow, Poland
| | - Y Tang
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - X Zhao
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA and State Key Lab of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China
| | - N Barišić
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA and Service de Physique de l'Etat Condensé, CEA-DSM-IRAMIS, F 91198 Gif-sur-Yvette, France and Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria
| | - M Greven
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
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