Amit Keren
Department of Physics, Technion-Israel Institute of Technology, Haifa 3200003, Israel
9 shared publications
Galina Bazalitsky
Physics Department, Technion-Israel Institute of Technology, Haifa 32000, Israel
5 shared publications
Rinat Ofer
Physics Department, Technion-Israel Institute of Technology, Haifa 32000, Israel
4 shared publications
Meni Shay
Department of Physics, Technion–Israel Institute of Technology, Haifa 32000, Israel
3 shared publications
A. E. Böhmer
Ames Laboratory, Ames, Iowa 50011, USA
2 shared publications
A. Kreyssig
Ames Laboratory, Ames, Iowa 50011, USA
2 shared publications

Latest Publications

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Cited by 22
- 1 November 2016
- Published by Elsevier in Journal of Magnetism and Magnetic Materials
Magnetization and transport properties of single crystalline RPd2P2 (R=Y, La–Nd, Sm–Ho, Yb)
by Gil Drachuck, Anna E. Böhmer, Sergey L. Bud'KO, Paul C. Canfield
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- 1 November 2016
- Published by Elsevier in Journal of Magnetism and Magnetic Materials
Magnetization and transport properties of single crystalline RPd2P2 (R=Y, La–Nd, Sm–Ho, Yb)
by Gil Drachuck, Anna E. Böhmer, Sergey L. Bud'KO, Paul C. Canfield
Cited by 22
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Cited by 165
- 16 September 2016
- Published by American Physical Society (APS) in Physical Review Letters
Origin of the Resistivity Anisotropy in the Nematic Phase of FeSe
by M. A. Tanatar, A. E. Böhmer, E. I. Timmons, M. Schütt, G. Drachuck, V. Taufour, K. Kothapalli, A. Kreyssig, S. L. Bud’ko, P. C. Canfield, et al.
The in-plane resistivity anisotropy is studied in strain-detwinned single crystals of FeSe. In contrast to other iron-based superconductors, FeSe does not develop long-range magnetic order below the tetragonal-to-orthorhombic transition at $T_{s} \approx 90 K$ . This allows for the disentanglement of the contributions to the resistivity anisotropy due to nematic and magnetic orders. Comparing direct transport and elastoresistivity measurements, we extract the intrinsic resistivity anisotropy of strain-free samples. The anisotropy peaks slightly below $T_{s}$ and decreases to nearly zero on cooling down to the superconducting transition. This behavior is consistent with a scenario in which the in-plane resistivity anisotropy is dominated by inelastic scattering by anisotropic spin fluctuations.
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- 16 September 2016
- Published by American Physical Society (APS) in Physical Review Letters
Open Access
Origin of the Resistivity Anisotropy in the Nematic Phase of FeSe
by M. A. Tanatar, A. E. Böhmer, E. I. Timmons, M. Schütt, G. Drachuck, V. Taufour, K. Kothapalli, A. Kreyssig, S. L. Bud’ko, P. C. Canfield, et al.
The in-plane resistivity anisotropy is studied in strain-detwinned single crystals of FeSe. In contrast to other iron-based superconductors, FeSe does not develop long-range magnetic order below the tetragonal-to-orthorhombic transition at $T_{s} \approx 90 K$ . This allows for the disentanglement of the contributions to the resistivity anisotropy due to nematic and magnetic orders. Comparing direct transport and elastoresistivity measurements, we extract the intrinsic resistivity anisotropy of strain-free samples. The anisotropy peaks slightly below $T_{s}$ and decreases to nearly zero on cooling down to the superconducting transition. This behavior is consistent with a scenario in which the in-plane resistivity anisotropy is dominated by inelastic scattering by anisotropic spin fluctuations.
Cited by 165
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Cited by 178
- 1 August 2016
- Published by American Physical Society (APS) in Physical Review B
Anisotropic thermodynamic and transport properties of single-crystalline ${CaKFe}_{4} {As}_{4}$
by W. R. Meier, T. Kong, U. S. Kaluarachchi, V. Taufour, N. H. Jo, G. Drachuck, A. E. Böhmer, S. M. Saunders, A. Sapkota, A. Kreyssig, et al.
Single-crystalline, single-phase ${CaKFe}_{4} {As}_{4}$ has been grown out of a high-temperature, quaternary melt. Temperature-dependent measurements of x-ray diffraction, anisotropic electrical resistivity, elastoresistivity, thermoelectric power, Hall effect, magnetization, and specific heat, combined with field-dependent measurements of electrical resistivity and field and pressure-dependent measurements of magnetization indicate that ${CaKFe}_{4} {As}_{4}$ is an ordered, stoichiometric, Fe-based superconductor with a superconducting critical temperature, $T_{c} = 35.0 \pm 0.2$ K. Other than superconductivity, there is no indication of any other phase transition for $1.8 K \leq T \leq 300$ K. All of these thermodynamic and transport data reveal striking similarities to those found for optimally or slightly overdoped $({Ba}_{1 - x} K_{x}) {Fe}_{2} {As}_{2}$ , suggesting that stoichiometric ${CaKFe}_{4} {As}_{4}$ is intrinsically close to what is referred to as “optimal-doped” on a generalized, Fe-based superconductor, phase diagram. The anisotropic superconducting upper critical field, $H_{c 2} (T)$ , of ${CaKFe}_{4} {As}_{4}$ was determined up to 630 kOe. The anisotropy parameter $γ (T) = H_{c 2}^{⊥} / H_{c 2}^{∥}$ , for $H$ applied perpendicular and parallel to the $c$ axis, decreases from $≃ 2.5$ at $T_{c}$ to $≃ 1.5$ at 25 K, which can be explained by interplay of paramagnetic pair breaking and orbital effects. The slopes of $d H_{c 2}^{∥} / d T ≃ - 44$ kOe/K and $d H_{c 2}^{⊥} / d T ≃ - 109$ kOe/K at $T_{c}$ yield an electron mass anisotropy of $m_{⊥} / m_{∥} ≃ 1 / 6$ and short Ginzburg-Landau coherence lengths $ξ_{∥} (0) ≃ 5.8 Å$ and $ξ_{⊥} (0) ≃ 14.3 Å$ . The value of $H_{c 2}^{⊥} (0)$ can be extrapolated to $≃ 920$ kOe, well above the BCS paramagnetic limit.
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- 1 August 2016
- Published by American Physical Society (APS) in Physical Review B
Open Access
Anisotropic thermodynamic and transport properties of single-crystalline ${CaKFe}_{4} {As}_{4}$
by W. R. Meier, T. Kong, U. S. Kaluarachchi, V. Taufour, N. H. Jo, G. Drachuck, A. E. Böhmer, S. M. Saunders, A. Sapkota, A. Kreyssig, et al.
Single-crystalline, single-phase ${CaKFe}_{4} {As}_{4}$ has been grown out of a high-temperature, quaternary melt. Temperature-dependent measurements of x-ray diffraction, anisotropic electrical resistivity, elastoresistivity, thermoelectric power, Hall effect, magnetization, and specific heat, combined with field-dependent measurements of electrical resistivity and field and pressure-dependent measurements of magnetization indicate that ${CaKFe}_{4} {As}_{4}$ is an ordered, stoichiometric, Fe-based superconductor with a superconducting critical temperature, $T_{c} = 35.0 \pm 0.2$ K. Other than superconductivity, there is no indication of any other phase transition for $1.8 K \leq T \leq 300$ K. All of these thermodynamic and transport data reveal striking similarities to those found for optimally or slightly overdoped $({Ba}_{1 - x} K_{x}) {Fe}_{2} {As}_{2}$ , suggesting that stoichiometric ${CaKFe}_{4} {As}_{4}$ is intrinsically close to what is referred to as “optimal-doped” on a generalized, Fe-based superconductor, phase diagram. The anisotropic superconducting upper critical field, $H_{c 2} (T)$ , of ${CaKFe}_{4} {As}_{4}$ was determined up to 630 kOe. The anisotropy parameter $γ (T) = H_{c 2}^{⊥} / H_{c 2}^{∥}$ , for $H$ applied perpendicular and parallel to the $c$ axis, decreases from $≃ 2.5$ at $T_{c}$ to $≃ 1.5$ at 25 K, which can be explained by interplay of paramagnetic pair breaking and orbital effects. The slopes of $d H_{c 2}^{∥} / d T ≃ - 44$ kOe/K and $d H_{c 2}^{⊥} / d T ≃ - 109$ kOe/K at $T_{c}$ yield an electron mass anisotropy of $m_{⊥} / m_{∥} ≃ 1 / 6$ and short Ginzburg-Landau coherence lengths $ξ_{∥} (0) ≃ 5.8 Å$ and $ξ_{⊥} (0) ≃ 14.3 Å$ . The value of $H_{c 2}^{⊥} (0)$ can be extrapolated to $≃ 920$ kOe, well above the BCS paramagnetic limit.
Cited by 178
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Cited by 45
- 10 September 2015
- Published by American Physical Society (APS) in Physical Review B
Correlation of the superconducting critical temperature with spin and orbital excitations in $({Ca}_{x} {La}_{1 - x}) ({Ba}_{1.75 - x} La$ $_{0.25 + x}) {Cu}_{3} O_{y}$ as measured by resonant inelastic x-ray scattering
by David Shai Ellis, Yao-Bo Huang, Paul Olalde-Velasco, Marcus Dantz, Jonathan Pelliciari, Gil Drachuck, Rinat Ofer, Galina Bazalitsky, Jorge Berger, Thorsten Schmitt, et al.
Electronic spin and orbital $(d d)$ excitation spectra of $({Ca}_{x} {La}_{1 - x}$ ) $({Ba}_{1.75 - x} {La}_{0.25 + x}) {Cu}_{3} O_{y}$ samples are measured by resonant inelastic x-ray scattering (RIXS). In this compound, $T_{c}$ of samples with identical hole dopings is strongly affected by the Ca/Ba substitution $x$ due to subtle variations in the lattice constants, while crystal symmetry and disorder as measured by linewidths are $x$ independent. We examine two extreme values of $x$ and two extreme values of hole-doping content $y$ corresponding to antiferromagnetic and superconducting states. The $x$ dependence of the spin-mode energies is approximately the same for both the antiferromagnetic and superconducting samples. This clearly demonstrates that RIXS is sensitive to the superexchange $J$ even in doped samples. A positive correlation between $J$ and the maximum of $T_{c}$ at optimal doping $(T_{c}^{max})$ is observed. We also measured the $x$ dependence of the $d_{x y} \to d_{x^{2} - y^{2}}$ and $d_{x z / y z} \to d_{x^{2} - y^{2}}$ orbital splittings. We infer that the effect of the unresolved $d_{3 z^{2} - r^{2}} \to d_{x^{2} \to y^{2}}$ excitation on $T_{c}^{max}$ is much smaller than the effect of $J$ . There appears to be dispersion in the $d_{x y} \to d_{x^{2} - y^{2}}$ peak of up to 0.05 eV. Our fitting furthermore indicates an asymmetric dispersion for the $d_{x z / y z} \to d_{x^{2} - y^{2}}$ excitation. A peak at $\sim 0.8$ eV is also observed and attributed to a $d d$ excitation in the chain layer.
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- 10 September 2015
- Published by American Physical Society (APS) in Physical Review B
Correlation of the superconducting critical temperature with spin and orbital excitations in $({Ca}_{x} {La}_{1 - x}) ({Ba}_{1.75 - x} La$ $_{0.25 + x}) {Cu}_{3} O_{y}$ as measured by resonant inelastic x-ray scattering
by David Shai Ellis, Yao-Bo Huang, Paul Olalde-Velasco, Marcus Dantz, Jonathan Pelliciari, Gil Drachuck, Rinat Ofer, Galina Bazalitsky, Jorge Berger, Thorsten Schmitt, et al.
Electronic spin and orbital $(d d)$ excitation spectra of $({Ca}_{x} {La}_{1 - x}$ ) $({Ba}_{1.75 - x} {La}_{0.25 + x}) {Cu}_{3} O_{y}$ samples are measured by resonant inelastic x-ray scattering (RIXS). In this compound, $T_{c}$ of samples with identical hole dopings is strongly affected by the Ca/Ba substitution $x$ due to subtle variations in the lattice constants, while crystal symmetry and disorder as measured by linewidths are $x$ independent. We examine two extreme values of $x$ and two extreme values of hole-doping content $y$ corresponding to antiferromagnetic and superconducting states. The $x$ dependence of the spin-mode energies is approximately the same for both the antiferromagnetic and superconducting samples. This clearly demonstrates that RIXS is sensitive to the superexchange $J$ even in doped samples. A positive correlation between $J$ and the maximum of $T_{c}$ at optimal doping $(T_{c}^{max})$ is observed. We also measured the $x$ dependence of the $d_{x y} \to d_{x^{2} - y^{2}}$ and $d_{x z / y z} \to d_{x^{2} - y^{2}}$ orbital splittings. We infer that the effect of the unresolved $d_{3 z^{2} - r^{2}} \to d_{x^{2} \to y^{2}}$ excitation on $T_{c}^{max}$ is much smaller than the effect of $J$ . There appears to be dispersion in the $d_{x y} \to d_{x^{2} - y^{2}}$ peak of up to 0.05 eV. Our fitting furthermore indicates an asymmetric dispersion for the $d_{x z / y z} \to d_{x^{2} - y^{2}}$ excitation. A peak at $\sim 0.8$ eV is also observed and attributed to a $d d$ excitation in the chain layer.
Cited by 45
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Cited by 13
- 17 September 2014
- Published by American Physical Society (APS) in Physical Review B
Relation between cuprate superconductivity and magnetism: A Raman study of ${(CaLa)}_{1} {(BaLa)}_{2} {Cu}_{3} O_{y}$
by Dirk Wulferding, Meni Shay, Gil Drachuck, Rinat Ofer, Galina Bazalitsky, Zaher Salman, Peter Lemmens, Amit Keren
We present an investigation of charge-compensated antiferromagnetic $({Ca}_{x} {La}_{1 - x}) {(Ba}_{1.75 - x} {La}_{0.25 + x} {) Cu}_{3} O_{y}$ single crystals using Raman scattering as well as muon spin rotation. In this system the parameter $x$ controls the Cu-O-Cu superexchange interaction via bond distances and buckling angles. The oxygen content $y$ controls the charge doping. In the absence of doping the two-magnon peak position is directly proportional to the superexchange strength $J$ . We find that both $x$ and $y$ affect the peak position considerably. The Néel temperature determined from muon spin rotation on the same samples independently confirms the strong dependence of the magnetic interaction on $x$ and $y$ . We find a considerable increase in the maximum superconducting transition temperature $T_{c}^{\max}$ with $J$ . This is strong evidence of the importance of orbital overlap to superconductivity in this family of cuprates.
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- 17 September 2014
- Published by American Physical Society (APS) in Physical Review B
Relation between cuprate superconductivity and magnetism: A Raman study of ${(CaLa)}_{1} {(BaLa)}_{2} {Cu}_{3} O_{y}$
by Dirk Wulferding, Meni Shay, Gil Drachuck, Rinat Ofer, Galina Bazalitsky, Zaher Salman, Peter Lemmens, Amit Keren
We present an investigation of charge-compensated antiferromagnetic $({Ca}_{x} {La}_{1 - x}) {(Ba}_{1.75 - x} {La}_{0.25 + x} {) Cu}_{3} O_{y}$ single crystals using Raman scattering as well as muon spin rotation. In this system the parameter $x$ controls the Cu-O-Cu superexchange interaction via bond distances and buckling angles. The oxygen content $y$ controls the charge doping. In the absence of doping the two-magnon peak position is directly proportional to the superexchange strength $J$ . We find that both $x$ and $y$ affect the peak position considerably. The Néel temperature determined from muon spin rotation on the same samples independently confirms the strong dependence of the magnetic interaction on $x$ and $y$ . We find a considerable increase in the maximum superconducting transition temperature $T_{c}^{\max}$ with $J$ . This is strong evidence of the importance of orbital overlap to superconductivity in this family of cuprates.
Cited by 13
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Cited by 10
- 31 March 2014
- Published by American Physical Society (APS) in Physical Review B
Linking dynamic and thermodynamic properties of cuprates: An angle-resolved photoemission study of (CaxLa1−x)(Ba1.75−xLa0.25+x)Cu3Oy(x=0.1and 0.4)
by Gil Drachuck, Elia Razzoli, Rinat Ofer, Galina Bazalitsky, R. S. Dhaka, Amit Kanigel, Ming Shi, Amit Keren
We report angle-resolved photoemission spectroscopy on two families of high-temperature superconductors ( ${Ca}_{x} {La}_{1 - x}) {(Ba}_{1.75 - x}$ La $_{0.25 + x} {)Cu}_{3} O_{y}$ with $x = 0.1$ ( $T_{c}^{\max} = 56$ K) and $x = 0.4$ ( $T_{c}^{\max} = 82$ K). The Fermi surface (FS) is found to be independent of $x$ or $y$ , and its size indicates extreme sample-surface overdoping. This universal FS allows the comparison of dynamical properties between superconductors of similar structure and identical doping, but different $T_{c}^{\max}$ . We find that the high-energy ( $| E | > 50$ meV) nodal velocity in the $x = 0.4$ family is higher than in the $x = 0.1$ family. The implied correlation between $T_{c}^{\max}$ and the hopping rate $t$ supports the notion of kinetic energy driven superconductivity in the cuprates. We also find that the antinodal gap is higher for the $x = 0.4$ family. DOI: http://dx.doi.org/10.1103/PhysRevB.89.121119 ©2014 American Physical Society
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- 31 March 2014
- Published by American Physical Society (APS) in Physical Review B
Linking dynamic and thermodynamic properties of cuprates: An angle-resolved photoemission study of (CaxLa1−x)(Ba1.75−xLa0.25+x)Cu3Oy(x=0.1and 0.4)
by Gil Drachuck, Elia Razzoli, Rinat Ofer, Galina Bazalitsky, R. S. Dhaka, Amit Kanigel, Ming Shi, Amit Keren
We report angle-resolved photoemission spectroscopy on two families of high-temperature superconductors ( ${Ca}_{x} {La}_{1 - x}) {(Ba}_{1.75 - x}$ La $_{0.25 + x} {)Cu}_{3} O_{y}$ with $x = 0.1$ ( $T_{c}^{\max} = 56$ K) and $x = 0.4$ ( $T_{c}^{\max} = 82$ K). The Fermi surface (FS) is found to be independent of $x$ or $y$ , and its size indicates extreme sample-surface overdoping. This universal FS allows the comparison of dynamical properties between superconductors of similar structure and identical doping, but different $T_{c}^{\max}$ . We find that the high-energy ( $| E | > 50$ meV) nodal velocity in the $x = 0.4$ family is higher than in the $x = 0.1$ family. The implied correlation between $T_{c}^{\max}$ and the hopping rate $t$ supports the notion of kinetic energy driven superconductivity in the cuprates. We also find that the antinodal gap is higher for the $x = 0.4$ family. DOI: http://dx.doi.org/10.1103/PhysRevB.89.121119 ©2014 American Physical Society
Cited by 10
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Cited by 37
- 27 February 2014
- Published by Springer Nature in Nature Communications
Comprehensive study of the spin-charge interplay in antiferromagnetic La2−xSrxCuO4
by Gil Drachuck, Elia Razzoli, Galina Bazalitski, Amit Kanigel, Christof Niedermayer, Ming Shi, Amit Keren
The origin of the pseudogap and its relationship with superconductivity in the cuprates remains vague. In particular, the interplay between the pseudogap and magnetism is mysterious. Here we investigate the newly discovered nodal gap in hole-doped cuprates using a combination of three experimental techniques applied to one, custom made, single crystal. The crystal is an antiferromagnetic La_2−xSr_xCuO₄ with x=1.92%. We perform angle-resolved photoemission spectroscopy measurements as a function of temperature and find: quasi-particle peaks, Fermi surface, anti-nodal gap and below 45 K a nodal gap. Muon spin rotation measurements ensure that the sample is indeed antiferromagnetic and that the doping is close, but below, the spin-glass phase boundary. We also perform elastic neutron scattering measurements and determine the thermal evolution of the commensurate and incommensurate magnetic order, where we find that a nodal gap opens well below the commensurate ordering at 140 K, and close to the incommensurate spin density wave ordering temperature of 30 K.
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- 27 February 2014
- Published by Springer Nature in Nature Communications
Open Access
Comprehensive study of the spin-charge interplay in antiferromagnetic La2−xSrxCuO4
by Gil Drachuck, Elia Razzoli, Galina Bazalitski, Amit Kanigel, Christof Niedermayer, Ming Shi, Amit Keren
The origin of the pseudogap and its relationship with superconductivity in the cuprates remains vague. In particular, the interplay between the pseudogap and magnetism is mysterious. Here we investigate the newly discovered nodal gap in hole-doped cuprates using a combination of three experimental techniques applied to one, custom made, single crystal. The crystal is an antiferromagnetic La_2−xSr_xCuO₄ with x=1.92%. We perform angle-resolved photoemission spectroscopy measurements as a function of temperature and find: quasi-particle peaks, Fermi surface, anti-nodal gap and below 45 K a nodal gap. Muon spin rotation measurements ensure that the sample is indeed antiferromagnetic and that the doping is close, but below, the spin-glass phase boundary. We also perform elastic neutron scattering measurements and determine the thermal evolution of the commensurate and incommensurate magnetic order, where we find that a nodal gap opens well below the commensurate ordering at 140 K, and close to the incommensurate spin density wave ordering temperature of 30 K.
Cited by 37
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Cited by 69
- 25 January 2013
- Published by American Physical Society (APS) in Physical Review Letters
Evolution from a Nodeless Gap to $d_{x^{2} - y^{2}}$ -Wave in Underdoped ${La}_{2 - x} {Sr}_{x} {CuO}_{4}$
by E. Razzoli, G. Drachuck, A. Keren, M. Radovic, N. C. Plumb, J. Chang, Y.-B. Huang, H. Ding, J. Mesot, M. Shi
Using angle-resolved photoemission spectroscopy (ARPES), it is revealed that the low-energy electronic excitation spectra of highly underdoped superconducting and nonsuperconducting ${La}_{2 - x} {Sr}_{x} {CuO}_{4}$ cuprates are gapped along the entire underlying Fermi surface at low temperatures. We show how the gap function evolves to a $d_{x^{2} - y^{2}}$ form with increasing temperature or doping, consistent with the vast majority of ARPES studies of cuprates. Our results provide essential information for uncovering the symmetry of the order parameter(s) in strongly underdoped cuprates, which is a prerequisite for understanding the pairing mechanism and how superconductivity emerges from a Mott insulator.
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- 25 January 2013
- Published by American Physical Society (APS) in Physical Review Letters
Evolution from a Nodeless Gap to $d_{x^{2} - y^{2}}$ -Wave in Underdoped ${La}_{2 - x} {Sr}_{x} {CuO}_{4}$
by E. Razzoli, G. Drachuck, A. Keren, M. Radovic, N. C. Plumb, J. Chang, Y.-B. Huang, H. Ding, J. Mesot, M. Shi
Using angle-resolved photoemission spectroscopy (ARPES), it is revealed that the low-energy electronic excitation spectra of highly underdoped superconducting and nonsuperconducting ${La}_{2 - x} {Sr}_{x} {CuO}_{4}$ cuprates are gapped along the entire underlying Fermi surface at low temperatures. We show how the gap function evolves to a $d_{x^{2} - y^{2}}$ form with increasing temperature or doping, consistent with the vast majority of ARPES studies of cuprates. Our results provide essential information for uncovering the symmetry of the order parameter(s) in strongly underdoped cuprates, which is a prerequisite for understanding the pairing mechanism and how superconductivity emerges from a Mott insulator.
Cited by 69
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Cited by 10
- 11 January 2013
- Published by IOP Publishing in Journal of Physics: Condensed Matter
Anisotropy of the upper critical fields and the paramagnetic Meissner effect in La_1.85Sr_0.15CuO₄single crystals
by I Felner, M I Tsindlekht, G Drachuck, A Keren
Optimally doped La(1.85)Sr(0.15)CuO(4) single crystals have been investigated by dc and ac magnetic measurements. These crystals have rectangular needle-like shapes with the long needle axis parallel to the crystallographic c axis (c-crystal) or parallel to the basal planes (a-crystal). In both crystals, the temperature dependence of the upper critical fields (H(C2)) and the surface critical field (H(C3)) were measured. The H-T phase diagram is presented. Close to T(C) = 35 K, for the c-crystal, γ(C) = H(C3)(c)/H(C2)(c) = 1.80(2), whereas for the a-crystal the γ(a) = H(C3)(a)/H(C2)(a) = 4.0(2) obtained is much higher than 1.69, predicted by the ideal mathematical model. At low applied dc fields, positive field-cooled branches known as the 'paramagnetic Meissner effect' (PME) are observed; their magnitude is inversely proportional to H. The anisotropic PME is observed in both a- and c-crystals, only when the applied field is along the basal planes. It is speculated that the high γ(a) and the PME are connected to each other.
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- 11 January 2013
- Published by IOP Publishing in Journal of Physics: Condensed Matter
Anisotropy of the upper critical fields and the paramagnetic Meissner effect in La_1.85Sr_0.15CuO₄single crystals
by I Felner, M I Tsindlekht, G Drachuck, A Keren
Optimally doped La(1.85)Sr(0.15)CuO(4) single crystals have been investigated by dc and ac magnetic measurements. These crystals have rectangular needle-like shapes with the long needle axis parallel to the crystallographic c axis (c-crystal) or parallel to the basal planes (a-crystal). In both crystals, the temperature dependence of the upper critical fields (H(C2)) and the surface critical field (H(C3)) were measured. The H-T phase diagram is presented. Close to T(C) = 35 K, for the c-crystal, γ(C) = H(C3)(c)/H(C2)(c) = 1.80(2), whereas for the a-crystal the γ(a) = H(C3)(a)/H(C2)(a) = 4.0(2) obtained is much higher than 1.69, predicted by the ideal mathematical model. At low applied dc fields, positive field-cooled branches known as the 'paramagnetic Meissner effect' (PME) are observed; their magnitude is inversely proportional to H. The anisotropic PME is observed in both a- and c-crystals, only when the applied field is along the basal planes. It is speculated that the high γ(a) and the PME are connected to each other.
Cited by 10
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Cited by 12
- 6 June 2012
- Published by Springer Nature in Journal of Superconductivity and Novel Magnetism
New Perspectives for Cuprate Research: (Ca x La1−x )(Ba1.75−x La0.25+x )Cu3O y Single Crystals
by Gil Drachuck, Meni Shay, Galina Bazalitsky, Rinat Ofer, Zaher Salman, Alex Amato, Christof Niedermayer, Dirk Wulferding, Peter Lemmens, Amit Keren
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- 6 June 2012
- Published by Springer Nature in Journal of Superconductivity and Novel Magnetism
New Perspectives for Cuprate Research: (Ca x La1−x )(Ba1.75−x La0.25+x )Cu3O y Single Crystals
by Gil Drachuck, Meni Shay, Galina Bazalitsky, Rinat Ofer, Zaher Salman, Alex Amato, Christof Niedermayer, Dirk Wulferding, Peter Lemmens, Amit Keren
Cited by 12

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