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D Hesse - One of the best experts on this subject based on the ideXlab platform.
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anisotropic ferroelectric properties of epitaxially twinned bi3 25la0 75ti3o12 thin films grown with three different orientations
Applied Physics Letters, 2002Co-Authors: D HesseAbstract:Epitaxially twinned (001)- , (118)- , and (104)-oriented La-substituted Bi4Ti3O12 (BLT) ferroelectric films have been grown by pulsed laser deposition on (001)- , (011)- , and (111)-oriented SrTiO3 single-crystal substrates, respectively, covered with SrRuO3. Well-defined (001)-oriented BLT films were grown at a substrate temperature as low as 600 °C. By x-ray diffraction characterization it has been found that the low-index three-dimensional epitaxial orientation relationship BLT(001)‖SrRuO3(001)‖SrTiO3(001); BLT[110]‖SrRuO3[100]‖SrTiO3[100] is valid for all epitaxially twinned BLT thin films grown on SrRuO3-covered SrTiO3 substrates in spite of their different orientations. The (104)-oriented BLT films showed an about 1.5 times higher remanent Polarization (2Pr=31.9 μC/cm2) than the (118)-oriented BLT films (2Pr=20.7 μC/cm2), while (001)-oriented BLT films revealed only a small Polarization Component (2Pr=1.1 μC/cm2), thus demonstrating the ferroelectric anisotropy.
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anisotropic ferroelectric properties of epitaxially twinned bi3 25la0 75ti3o12 thin films grown with three different orientations
Applied Physics Letters, 2002Co-Authors: Ho Nyung Lee, D HesseAbstract:Epitaxially twinned (001)- , (118)- , and (104)-oriented La-substituted Bi4Ti3O12 (BLT) ferroelectric films have been grown by pulsed laser deposition on (001)- , (011)- , and (111)-oriented SrTiO3 single-crystal substrates, respectively, covered with SrRuO3. Well-defined (001)-oriented BLT films were grown at a substrate temperature as low as 600 °C. By x-ray diffraction characterization it has been found that the low-index three-dimensional epitaxial orientation relationship BLT(001)‖SrRuO3(001)‖SrTiO3(001); BLT[110]‖SrRuO3[100]‖SrTiO3[100] is valid for all epitaxially twinned BLT thin films grown on SrRuO3-covered SrTiO3 substrates in spite of their different orientations. The (104)-oriented BLT films showed an about 1.5 times higher remanent Polarization (2Pr=31.9 μC/cm2) than the (118)-oriented BLT films (2Pr=20.7 μC/cm2), while (001)-oriented BLT films revealed only a small Polarization Component (2Pr=1.1 μC/cm2), thus demonstrating the ferroelectric anisotropy.
Venkatraman Gopalan - One of the best experts on this subject based on the ideXlab platform.
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origin of piezoelectric response under a biased scanning probe microscopy tip across a 180 ferroelectric domain wall
Physical Review B, 2012Co-Authors: Eugene A Eliseev, Sergei V Kalinin, Anna N Morozovska, Ryan Haislmaier, Tom T A Lummen, Venkatraman GopalanAbstract:The piezoelectric response of a material under a nanoscale biased tip scanned across a sample in piezoelectric force microscopy (PFM) provides insight into the structure and dynamics of domain walls in ferroelectrics. While the vertical displacements of the tip under piezoelectric deformations of the sample have been reasonably explained, the origin of the lateral twisting of the tip remains unclear. This poses a serious problem when combining vertical and lateral signals to create vector PFM maps of Polarization distribution in ferroelectrics. Using a combination offinite element modeling and analytical theory, and by comparison with prior experimental work across a single antiparallel domain wall on the (0001) surface of LiNbO3, we unequivocally show that the lateral signal originates from a shear displacement of the surface. We show that there are two types of lateral signals, one arising from the d15 shear deformation, and the other from the d22 lateral deformation. The vertical PFM signal surprisingly shows equal contributions from the d33 (leading to normal displacements) and d15 (leading to shear displacement) coefficients. We also show that an averaging of the PFM signal over a finite contact area of the tip, as experimentally observed, is essential to understanding the line shape of the PFM responses across the wall. After clarifying the origin of the nanoscale PFM signals, we conclude that, in general, a vertical signal does not automatically indicate a Polarization Component out of the surface, while a lateral signal does not automatically indicate an in-plane Polarization Component. Without a detailed theory or simulation especially in materials with nanoscale domain structures, ferroelectric relaxors, and morphotropic compositions, such assumptions may lead to incorrect domain and wall interpretations. The proposed model and numerical simulation method could be applied to all piezoelectric materials.
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influence of anisotropic strain on the dielectric and ferroelectric properties of srtio 3 thin films on dysco 3 substrates
Physical Review B, 2009Co-Authors: Michael D Biegalski, Eftihia Vlahos, Guang Sheng, M Bernhagen, P Reiche, Reinhard Uecker, S K Streiffer, Long Qing Chen, Venkatraman GopalanAbstract:The in-plane dielectric and ferroelectric properties of coherent anisotropically strained ${\text{SrTiO}}_{3}$ thin films grown on orthorhombic (101) ${\text{DyScO}}_{3}$ substrates were examined as a function of the angle between the applied electric field and the principal directions of the substrate. The dielectric permittivity revealed two distinct maxima as a function of temperature along the ${[100]}_{p}$ and ${[010]}_{p}$ ${\text{SrTiO}}_{3}$ pseudocubic directions. These data, in conjunction with optical second-harmonic generation, show that the switchable ferroelectric Polarization develops first predominantly along the in-plane axis with the larger tensile strain before developing a Polarization Component along the perpendicular direction with smaller strain as well, leading to domain twinning at the lower temperature. Finally, weak signatures in the dielectric and second-harmonic generation response were detected at the ${\text{SrTiO}}_{3}$ tilt transition close to 165 K. These studies indicate that anisotropic biaxial strain can lead to new ferroelectric domain reorientation transitions that are not observed in isotropically strained films.
F R Wesselmann - One of the best experts on this subject based on the ideXlab platform.
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Polarization transfer observables in elastic electron proton scattering at q2 2 5 5 2 6 8 and 8 5 gev2
Physical Review C, 2017Co-Authors: A J R Puckett, E Brash, W Luo, M Meziane, L Pentchev, C F Perdrisat, V Punjabi, M Jones, F R WesselmannAbstract:Author(s): Puckett, AJR; Brash, EJ; Jones, MK; Luo, W; Meziane, M; Pentchev, L; Perdrisat, CF; Punjabi, V; Wesselmann, FR; Afanasev, A; Ahmidouch, A; Albayrak, I; Aniol, KA; Arrington, J; Asaturyan, A; Baghdasaryan, H; Benmokhtar, F; Bertozzi, W; Bimbot, L; Bosted, P; Boeglin, W; Butuceanu, C; Carter, P; Chernenko, S; Christy, ME; Commisso, M; Cornejo, JC; Covrig, S; Danagoulian, S; Daniel, A; Davidenko, A; Day, D; Dhamija, S; Dutta, D; Ent, R; Frullani, S; Fenker, H; Frlez, E; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Goncharenko, Y; Hafidi, K; Hamilton, D; Higinbotham, DW; Hinton, W; Horn, T; Hu, B; Huang, J; Huber, GM; Jensen, E; Keppel, C; Khandaker, M; King, P; Kirillov, D; Kohl, M; Kravtsov, V; Kumbartzki, G; Li, Y; Mamyan, V; Margaziotis, DJ; Marsh, A; Matulenko, Y; Maxwell, J; Mbianda, G; Meekins, D; Melnik, Y; Miller, J; Mkrtchyan, A; Mkrtchyan, H; Moffit, B; Moreno, O; Mulholland, J; Narayan, A; Nedev, S; Nuruzzaman; Piasetzky, E; Pierce, W; Piskunov, NM; Prok, Y; Ransome, RD; Razin, DS; Reimer, P; Reinhold, J | Abstract: Background: Interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using Polarization observables, of the rapid decrease of the ratio GEp/GMp of the proton's electric and magnetic form factors for momentum transfers Q21 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique. Purpose: The GEp-III and GEp-2γ experiments were carried out in Jefferson Laboratory's (JLab's) Hall C from 2007 to 2008, to extend the knowledge of GEp/GMp to the highest practically achievable Q2 given the maximum beam energy of 6 GeV and to search for effects beyond the Born approximation in Polarization transfer observables of elastic ∫ - p scattering. This article provides an expanded description of the common experimental apparatus and data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance dataset of the GEp-2γ experiment. Methods: Polarization transfer observables in elastic ∫ - p→∫ - scattering were measured at central Q2 values of 2.5, 5.2, 6.8, and 8.54 GeV2. At Q2=2.5GeV2, data were obtained for central values of the virtual photon Polarization parameter ϵ of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and measured the Polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2γ data are significantly reduced at ϵ=0.632 and 0.783 relative to the original publication. Conclusions: The final GEp-III results show that the decrease with Q2 of GEp/GMp continues to Q2=8.5GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At Q2=8.5GeV2, GEp/GMp remains positive but is consistent with zero. At Q2=2.5GeV2, GEp/GMp derived from the Polarization Component ratio R-Pt/P shows no statistically significant ϵ dependence, as expected in the Born approximation. On the other hand, the ratio P""/P""Born of the longitudinal Polarization transfer Component to its Born value shows an enhancement of roughly 1.7% at ϵ=0.783 relative to ϵ=0.149, with ≈2.2σ significance based on the total uncertainty, implying a similar effect in the transverse Component Pt that cancels in the ratio R.
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Polarization transfer observables in elastic electron proton scattering at q2 2 5 5 2 6 8 and 8 5 gev2
Physical Review C, 2017Co-Authors: A J R Puckett, E Brash, W Luo, M Meziane, L Pentchev, C F Perdrisat, V Punjabi, M Jones, F R WesselmannAbstract:Background: Interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using Polarization observables, of the rapid decrease of the ratio GEp/GMp of the proton's electric and magnetic form factors for momentum transfers Q21 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique. Purpose: The GEp-III and GEp-2γ experiments were carried out in Jefferson Laboratory's (JLab's) Hall C from 2007 to 2008, to extend the knowledge of GEp/GMp to the highest practically achievable Q2 given the maximum beam energy of 6 GeV and to search for effects beyond the Born approximation in Polarization transfer observables of elastic ∫ - p scattering. This article provides an expanded description of the common experimental apparatus and data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance dataset of the GEp-2γ experiment. Methods: Polarization transfer observables in elastic ∫ - p→∫ - scattering were measured at central Q2 values of 2.5, 5.2, 6.8, and 8.54 GeV2. At Q2=2.5GeV2, data were obtained for central values of the virtual photon Polarization parameter ϵ of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and measured the Polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2γ data are significantly reduced at ϵ=0.632 and 0.783 relative to the original publication. Conclusions: The final GEp-III results show that the decrease with Q2 of GEp/GMp continues to Q2=8.5GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At Q2=8.5GeV2, GEp/GMp remains positive but is consistent with zero. At Q2=2.5GeV2, GEp/GMp derived from the Polarization Component ratio R-Pt/P shows no statistically significant ϵ dependence, as expected in the Born approximation. On the other hand, the ratio P""/P""Born of the longitudinal Polarization transfer Component to its Born value shows an enhancement of roughly 1.7% at ϵ=0.783 relative to ϵ=0.149, with ≈2.2σ significance based on the total uncertainty, implying a similar effect in the transverse Component Pt that cancels in the ratio R.
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Polarization transfer observables in elastic electron proton scattering at q2 2 5 5 2 6 8 and 8 5 gev2
Physical Review C, 2017Co-Authors: A J R Puckett, E Brash, M K Jones, W Luo, M Meziane, L Pentchev, C F Perdrisat, V Punjabi, F R WesselmannAbstract:Background: Interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using Polarization observables, of the rapid decrease of the ratio GEp/GMp of the proton's electric and magnetic form factors for momentum transfers Q2≳1 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique. Purpose: The GEp-III and GEp-2γ experiments were carried out in Jefferson Laboratory's (JLab's) Hall C from 2007 to 2008, to extend the knowledge of GEp/GMp to the highest practically achievable Q2 given the maximum beam energy of 6 GeV and to search for effects beyond the Born approximation in Polarization transfer observables of elastic ep scattering. This article provides an expanded description of the common experimental apparatus and data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance dataset of the GEp-2γ experiment. Methods: Polarization transfer observables in elastic ep→ep scattering were measured at central Q2 values of 2.5, 5.2, 6.8, and 8.54 GeV2. At Q2=2.5GeV2, data were obtained for central values of the virtual photon Polarization parameter e of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and measured the Polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2γ data are significantly reduced at e=0.632 and 0.783 relative to the original publication. Conclusions: The final GEp-III results show that the decrease with Q2 of GEp/GMp continues to Q2=8.5GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At Q2=8.5GeV2, GEp/GMp remains positive but is consistent with zero. At Q2=2.5GeV2, GEp/GMp derived from the Polarization Component ratio R∝Pt/Pl shows no statistically significant e dependence, as expected in the Born approximation. On the other hand, the ratio Pl/PlBorn of the longitudinal Polarization transfer Component to its Born value shows an enhancement of roughly 1.7% at e=0.783 relative to e=0.149, with ≈2.2σ significance based on the total uncertainty, implying a similar effect in the transverse Component Pt that cancels in the ratio R.
E Brash - One of the best experts on this subject based on the ideXlab platform.
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Polarization transfer observables in elastic electron proton scattering at q2 2 5 5 2 6 8 and 8 5 gev2
Physical Review C, 2017Co-Authors: A J R Puckett, E Brash, W Luo, M Meziane, L Pentchev, C F Perdrisat, V Punjabi, M Jones, F R WesselmannAbstract:Author(s): Puckett, AJR; Brash, EJ; Jones, MK; Luo, W; Meziane, M; Pentchev, L; Perdrisat, CF; Punjabi, V; Wesselmann, FR; Afanasev, A; Ahmidouch, A; Albayrak, I; Aniol, KA; Arrington, J; Asaturyan, A; Baghdasaryan, H; Benmokhtar, F; Bertozzi, W; Bimbot, L; Bosted, P; Boeglin, W; Butuceanu, C; Carter, P; Chernenko, S; Christy, ME; Commisso, M; Cornejo, JC; Covrig, S; Danagoulian, S; Daniel, A; Davidenko, A; Day, D; Dhamija, S; Dutta, D; Ent, R; Frullani, S; Fenker, H; Frlez, E; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Goncharenko, Y; Hafidi, K; Hamilton, D; Higinbotham, DW; Hinton, W; Horn, T; Hu, B; Huang, J; Huber, GM; Jensen, E; Keppel, C; Khandaker, M; King, P; Kirillov, D; Kohl, M; Kravtsov, V; Kumbartzki, G; Li, Y; Mamyan, V; Margaziotis, DJ; Marsh, A; Matulenko, Y; Maxwell, J; Mbianda, G; Meekins, D; Melnik, Y; Miller, J; Mkrtchyan, A; Mkrtchyan, H; Moffit, B; Moreno, O; Mulholland, J; Narayan, A; Nedev, S; Nuruzzaman; Piasetzky, E; Pierce, W; Piskunov, NM; Prok, Y; Ransome, RD; Razin, DS; Reimer, P; Reinhold, J | Abstract: Background: Interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using Polarization observables, of the rapid decrease of the ratio GEp/GMp of the proton's electric and magnetic form factors for momentum transfers Q21 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique. Purpose: The GEp-III and GEp-2γ experiments were carried out in Jefferson Laboratory's (JLab's) Hall C from 2007 to 2008, to extend the knowledge of GEp/GMp to the highest practically achievable Q2 given the maximum beam energy of 6 GeV and to search for effects beyond the Born approximation in Polarization transfer observables of elastic ∫ - p scattering. This article provides an expanded description of the common experimental apparatus and data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance dataset of the GEp-2γ experiment. Methods: Polarization transfer observables in elastic ∫ - p→∫ - scattering were measured at central Q2 values of 2.5, 5.2, 6.8, and 8.54 GeV2. At Q2=2.5GeV2, data were obtained for central values of the virtual photon Polarization parameter ϵ of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and measured the Polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2γ data are significantly reduced at ϵ=0.632 and 0.783 relative to the original publication. Conclusions: The final GEp-III results show that the decrease with Q2 of GEp/GMp continues to Q2=8.5GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At Q2=8.5GeV2, GEp/GMp remains positive but is consistent with zero. At Q2=2.5GeV2, GEp/GMp derived from the Polarization Component ratio R-Pt/P shows no statistically significant ϵ dependence, as expected in the Born approximation. On the other hand, the ratio P""/P""Born of the longitudinal Polarization transfer Component to its Born value shows an enhancement of roughly 1.7% at ϵ=0.783 relative to ϵ=0.149, with ≈2.2σ significance based on the total uncertainty, implying a similar effect in the transverse Component Pt that cancels in the ratio R.
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Polarization transfer observables in elastic electron proton scattering at q2 2 5 5 2 6 8 and 8 5 gev2
Physical Review C, 2017Co-Authors: A J R Puckett, E Brash, W Luo, M Meziane, L Pentchev, C F Perdrisat, V Punjabi, M Jones, F R WesselmannAbstract:Background: Interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using Polarization observables, of the rapid decrease of the ratio GEp/GMp of the proton's electric and magnetic form factors for momentum transfers Q21 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique. Purpose: The GEp-III and GEp-2γ experiments were carried out in Jefferson Laboratory's (JLab's) Hall C from 2007 to 2008, to extend the knowledge of GEp/GMp to the highest practically achievable Q2 given the maximum beam energy of 6 GeV and to search for effects beyond the Born approximation in Polarization transfer observables of elastic ∫ - p scattering. This article provides an expanded description of the common experimental apparatus and data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance dataset of the GEp-2γ experiment. Methods: Polarization transfer observables in elastic ∫ - p→∫ - scattering were measured at central Q2 values of 2.5, 5.2, 6.8, and 8.54 GeV2. At Q2=2.5GeV2, data were obtained for central values of the virtual photon Polarization parameter ϵ of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and measured the Polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2γ data are significantly reduced at ϵ=0.632 and 0.783 relative to the original publication. Conclusions: The final GEp-III results show that the decrease with Q2 of GEp/GMp continues to Q2=8.5GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At Q2=8.5GeV2, GEp/GMp remains positive but is consistent with zero. At Q2=2.5GeV2, GEp/GMp derived from the Polarization Component ratio R-Pt/P shows no statistically significant ϵ dependence, as expected in the Born approximation. On the other hand, the ratio P""/P""Born of the longitudinal Polarization transfer Component to its Born value shows an enhancement of roughly 1.7% at ϵ=0.783 relative to ϵ=0.149, with ≈2.2σ significance based on the total uncertainty, implying a similar effect in the transverse Component Pt that cancels in the ratio R.
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Polarization transfer observables in elastic electron proton scattering at q2 2 5 5 2 6 8 and 8 5 gev2
Physical Review C, 2017Co-Authors: A J R Puckett, E Brash, M K Jones, W Luo, M Meziane, L Pentchev, C F Perdrisat, V Punjabi, F R WesselmannAbstract:Background: Interest in the behavior of nucleon electromagnetic form factors at large momentum transfers has steadily increased since the discovery, using Polarization observables, of the rapid decrease of the ratio GEp/GMp of the proton's electric and magnetic form factors for momentum transfers Q2≳1 GeV2, in strong disagreement with previous extractions of this ratio using the traditional Rosenbluth separation technique. Purpose: The GEp-III and GEp-2γ experiments were carried out in Jefferson Laboratory's (JLab's) Hall C from 2007 to 2008, to extend the knowledge of GEp/GMp to the highest practically achievable Q2 given the maximum beam energy of 6 GeV and to search for effects beyond the Born approximation in Polarization transfer observables of elastic ep scattering. This article provides an expanded description of the common experimental apparatus and data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance dataset of the GEp-2γ experiment. Methods: Polarization transfer observables in elastic ep→ep scattering were measured at central Q2 values of 2.5, 5.2, 6.8, and 8.54 GeV2. At Q2=2.5GeV2, data were obtained for central values of the virtual photon Polarization parameter e of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and measured the Polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2γ data are significantly reduced at e=0.632 and 0.783 relative to the original publication. Conclusions: The final GEp-III results show that the decrease with Q2 of GEp/GMp continues to Q2=8.5GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At Q2=8.5GeV2, GEp/GMp remains positive but is consistent with zero. At Q2=2.5GeV2, GEp/GMp derived from the Polarization Component ratio R∝Pt/Pl shows no statistically significant e dependence, as expected in the Born approximation. On the other hand, the ratio Pl/PlBorn of the longitudinal Polarization transfer Component to its Born value shows an enhancement of roughly 1.7% at e=0.783 relative to e=0.149, with ≈2.2σ significance based on the total uncertainty, implying a similar effect in the transverse Component Pt that cancels in the ratio R.
G Bauer - One of the best experts on this subject based on the ideXlab platform.
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spin backflow and ac voltage generation by spin pumping and the inverse spin hall effect
Physical Review Letters, 2013Co-Authors: Hujun Jiao, G BauerAbstract:The spin current pumped by a precessing ferromagnet into an adjacent normal metal has a constant Polarization Component parallel to the precession axis and a rotating one normal to the magnetization. The former is now routinely detected as a dc voltage induced by the inverse spin Hall effect (ISHE). Here we compute ac ISHE voltages much larger than the dc signals for various material combinations and discuss optimal conditions to observe the effect. The backflow of spin is shown to be essential to distill parameters from measured ISHE voltages for both dc and ac configurations.