Stable high-pressure phases in the H-S system determined by chemically reacting hydrogen and sulfur
Alexander F. Goncharov, Sergey S. Lobanov, Vitali B. Prakapenka, and Eran Greenberg
Phys. Rev. B 95, 140101(R) (2017) - Published 10 April, 2017
Se Kwon Kim, Kyung-Jin Lee, and Yaroslav Tserkovnyak
Phys. Rev. B 95, 140404(R) (2017) - Published 14 April, 2017
Skyrmions, swirling magnetic textures with a topological character, have been gaining much attention in spintronics due to the fundamental interest as well as their touted utility as information carriers in ultradense and low-power memory devices. Generally, a skyrmion behaves as a massive particle moving in a viscous medium and experiencing a Magnus force, which is proportional to its winding number and the spin polarization of the magnet. There is a class of tunable ferrimagnets, such as rare-earth transition-metal alloys, exhibiting the angular momentum compensation point at which the spin density changes sign. This raises the possibility to engineer both the magnitude and the sign of the Magnus force acting on the skyrmions in the ferrimagnets. The authors exploit this to suggest that ferrimagnetic skyrmions can exhibit snake trajectories along the line of the vanishing spin density, analogous to the snake orbits of electrons in a nonuniform magnetic field. This can be utilized as dynamically self-focusing racetracks for skyrmions, paving the way for skyrmion-based memory devices.
Xi Chen, Karalee Jarvis, Sean Sullivan, Yutao Li, Jianshi Zhou, and Li Shi
Phys. Rev. B 95, 144310 (2017) - Published 27 April, 2017
The strong spin-spin exchange interaction in some low-dimensional magnetic materials can give rise to a high group velocity and thermal conductivity contribution from magnons, which are energy quanta of collective spin excitations. Examples are the incommensurate layered compounds (Sr,Ca,La)CuO, with strong antiferromagnetic interaction along the ladders. The effects of grain boundaries and defects on quasi-one-dimensional magnon transport in these compounds are not well understood. Here, the authors report the microstructures and anisotropic thermal transport properties of textured SrCuO. TEM clearly reveals nanolayered grains and the presence of dislocations and planar defects. The thermal conductivity contribution and mean free paths of magnons in the textured samples are evaluated with the use of a kinetic model for one-dimensional magnon transport, and found to be suppressed significantly compared to single crystals at low temperatures. The experimental results can be explained by a one-dimensional magnon-defect scattering model, provided that the magnon–grain boundary scattering mean free path in the anisotropic magnetic structure is smaller than the average length of these nanolayers along the axis. The finding suggests low transmission coefficients for energy-carrying magnons across grain boundaries.
So Takei, Yaroslav Tserkovnyak, and Masoud Mohseni
Phys. Rev. B 95, 144402 (2017) - Published 4 April, 2017
Spin Hall phenomena are a collection of relativistic spin-orbit coupling effects that permit control and detection of magnetization dynamics in magnetic materials with electrical currents. In spintronics, they have been studied extensively in bilayer structures consisting of a magnetically ordered material interfaced by a current-carrying paramagnetic metal with strong spin-orbit coupling. In this work, the authors propose the magnetic phase qubit, the macroscopic quantum spintronic device that can be built from such bilayers and that permits full electrical control and readout via spin Hall phenomena. The device is an example of a macroscopic qubit that can be constructed from solid-state materials and so should offer the same advantages as the superconducting qubits of strong inter-qubit coupling and scalability. An estimate of the relevant physical parameters based on current spintronic technology gives a qubit operational temperature that is more than an order of magnitude higher than for existing superconducting qubits, thus opening the possibility of macroscopic quantum information processing at temperatures above the dilution refrigerator range. The authors also show that a coupled array of these qubits can realize a quantum annealer, which could be used to solve certain hard optimization problems and machine learning tasks.
S. Shihab, L. Thevenard, A. Lemaître, and C. Gourdon
Phys. Rev. B 95, 144411 (2017) - Published 12 April, 2017
In ferromagnetic layers, spin-wave modes can be excited by a laser pulse launching the magnetization out of equilibrium and into precession. The trajectory of the magnetization vector can be fully reconstructed using different magneto-optical effects, generally admitted to give a faithful picture of the dynamics. The authors show that this is not always the case and that magneto-optical effects can indeed be deceiving. For this, they study the case of a weakly absorbing ferromagnet, the semiconductor GaMnAs, in which perpendicular standing spin waves are excited by a laser pulse. Quite counterintuitively, the optical detection shows the first two excited modes to be of opposite chirality, whereas theory tells us the spin waves actually rotate in the same direction. The paper demonstrates that this unexpected and surprising effect is a pure optical illusion. It can perfectly be explained by taking into account absorption and optical phase shift inside the layer, the latter being particularly strong in weakly absorbing layers. These results provide a correct identification of spin-wave modes, enabling a trustworthy estimation of their respective weight as well as an unambiguous determination of the spin stiffness parameter.
K. A. Ross, J. M. Brown, R. J. Cava, J. W. Krizan, S. E. Nagler, J. A. Rodriguez-Rivera, and M. B. Stone
Phys. Rev. B 95, 144414 (2017) - Published 13 April, 2017
Quantum effects in magnetic materials are prevalent when the magnetic ions support spin-½ moments, as in Cu-based materials. Strong quantum effects can also be achieved when the large angular momentum states are reduced to an effective spin-½ subspace (=½) by the combined effect of spin-orbit coupling and the crystal electric field. A consequence of this is the introduction of anisotropy to the g tensor and the effective exchange interactions. Such anisotropic =½ models have recently been applied successfully to rare-earth based frustrated pyrochlore materials, where they are found to lead to particularly rich phenomenology for XY-like tensors. Here, it is shown that a similar quantum model should apply to the recently discovered “high temperature” Co pyrochlores, NaCaCoF and NaSrCoF, based on a fit to their single ion levels as measured via inelastic neutron scattering. The effect of the intrinsic crystalline disorder on the anisotropy of the =½ moments in these materials is also estimated.
E. B. Sonin
Phys. Rev. B 95, 144432 (2017) - Published 27 April, 2017
Recently, it was suggested that metastable spin supercurrents (spin superfluidity) are possible in the magnon condensate observed in yttrium iron garnet (YIG) magnetic films under strong magnon pumping. In YIG, magnetic anisotropy is rather weak, and this material can be treated as an isotropic ferromagnet. Its order-parameter space is a sphere of radius equal to the spontaneous magnetization . A current state maps on the equatorial circumference on the sphere, and topology of the sphere allows us to continuously transform the equatorial circumference to the point. This rules out metastable current states. Only easy-plane anisotropy reducing the order-parameter space from the sphere to the equatorial circumference makes current states topologically stable. However, by pumping magnons to the isotropic ferromagnet in a magnetic field, it is possible to support a strongly nonequilibrium state with fixed average . This confines the precessing spin to an “easy plane” of dynamical rather than topological origin and makes metastable spin currents possible. But final judgment requires evaluation of the Landau superfluidity criterion as done in the present work. The conclusion is that spin superfluidity in YIG films is possible in principle, although the recently published claim of its observation is not justified.
L. J. Bannenberg, K. Kakurai, P. Falus, E. Lelièvre-Berna, R. Dalgliesh, C. D. Dewhurst, F. Qian, Y. Onose, Y. Endoh, Y. Tokura, and C. Pappas
Phys. Rev. B 95, 144433 (2017) - Published 28 April, 2017
Chiral magnetism plays an increasingly important role in condensed matter investigations driven by the discovery of exotic spin textures, such as the topologically protected chiral skyrmions that can form a lattice under magnetic fields. The nature and universality of the phase diagram in cubic chiral magnets has been the subject of numerous experimental and theoretical investigations, including the transition to the helimagnetic state. In MnSi, the archetypal system in this family, this transition is of first order and involves a precursor phase, where strong chiral fluctuating correlations build up. This work presents an experimental investigation of the structural and dynamical aspects of the phase transition in FeCoSi, a system that belongs to the same family as MnSi but with the additional possibility to tune important physical interactions and parameters through variation of the Fe and Co concentration. In this system, the combination of small-angle neutron scattering and neutron spin echo spectroscopy uncovers that the scenario of the transition is qualitatively very different from that in MnSi. This goes beyond what can be expected from a comparison of the relevant length scales and thus challenges the validity of a universal approach to the helimagnetic transition in cubic chiral magnets.
Alexander F. Goncharov, Sergey S. Lobanov, Vitali B. Prakapenka, and Eran Greenberg
Phys. Rev. B 95, 140101(R) (2017) - Published 10 April, 2017
Cécile Crosnier de Bellaistre, Alain Aspect, Antoine Georges, and Laurent Sanchez-Palencia
Phys. Rev. B 95, 140201(R) (2017) - Published 4 April, 2017
Chandan Setty, Philip W. Phillips, and Awadhesh Narayan
Phys. Rev. B 95, 140202(R) (2017) - Published 27 April, 2017
Tanmoy Ghosh, Takashi Fukuda, Tomoyuki Kakeshita, S. N. Kaul, and P. K. Mukhopadhyay
Phys. Rev. B 95, 140401(R) (2017) - Published 3 April, 2017
J. Liu, L. J. Cornelissen, J. Shan, T. Kuschel, and B. J. van Wees
Phys. Rev. B 95, 140402(R) (2017) - Published 10 April, 2017
K. Rolfs, S. Tóth, E. Pomjakushina, D. T. Adroja, D. Khalyavin, and K. Conder
Phys. Rev. B 95, 140403(R) (2017) - Published 10 April, 2017
Se Kwon Kim, Kyung-Jin Lee, and Yaroslav Tserkovnyak
Phys. Rev. B 95, 140404(R) (2017) - Published 14 April, 2017
Skyrmions, swirling magnetic textures with a topological character, have been gaining much attention in spintronics due to the fundamental interest as well as their touted utility as information carriers in ultradense and low-power memory devices. Generally, a skyrmion behaves as a massive particle moving in a viscous medium and experiencing a Magnus force, which is proportional to its winding number and the spin polarization of the magnet. There is a class of tunable ferrimagnets, such as rare-earth transition-metal alloys, exhibiting the angular momentum compensation point at which the spin density changes sign. This raises the possibility to engineer both the magnitude and the sign of the Magnus force acting on the skyrmions in the ferrimagnets. The authors exploit this to suggest that ferrimagnetic skyrmions can exhibit snake trajectories along the line of the vanishing spin density, analogous to the snake orbits of electrons in a nonuniform magnetic field. This can be utilized as dynamically self-focusing racetracks for skyrmions, paving the way for skyrmion-based memory devices.
Théo Mathurin, Stefano Giordano, Yannick Dusch, Nicolas Tiercelin, Philippe Pernod, and Vladimir Preobrazhensky
Phys. Rev. B 95, 140405(R) (2017) - Published 25 April, 2017
P. Lecheminant and A. M. Tsvelik
Phys. Rev. B 95, 140406(R) (2017) - Published 26 April, 2017
E. Piatti, D. Daghero, G. A. Ummarino, F. Laviano, J. R. Nair, R. Cristiano, A. Casaburi, C. Portesi, A. Sola, and R. S. Gonnelli
Phys. Rev. B 95, 140501(R) (2017) - Published 7 April, 2017
D. Stornaiuolo, D. Massarotti, R. Di Capua, P. Lucignano, G. P. Pepe, M. Salluzzo, and F. Tafuri
Phys. Rev. B 95, 140502(R) (2017) - Published 7 April, 2017
Takeshi Mizushima, Kota Masuda, and Muneto Nitta
Phys. Rev. B 95, 140503(R) (2017) - Published 20 April, 2017
Pasquale Marra and Mario Cuoco
Phys. Rev. B 95, 140504(R) (2017) - Published 24 April, 2017
P. K. Biswas, A. Iyo, Y. Yoshida, H. Eisaki, K. Kawashima, and A. D. Hillier
Phys. Rev. B 95, 140505(R) (2017) - Published 24 April, 2017
Wojciech Brzezicki, Andrzej M. Oleś, and Mario Cuoco
Phys. Rev. B 95, 140506(R) (2017) - Published 25 April, 2017
Adrian Del Maestro and Bernd Rosenow
Phys. Rev. B 95, 140507(R) (2017) - Published 25 April, 2017
Christopher D. O'Neill, Dmitry A. Sokolov, Andreas Hermann, Alexei Bossak, Christopher Stock, and Andrew D. Huxley
Phys. Rev. B 95, 144101 (2017) - Published 3 April, 2017
Kang Xia, Jian Sun, Chris J. Pickard, Dennis D. Klug, and Richard J. Needs
Phys. Rev. B 95, 144102 (2017) - Published 4 April, 2017
G. Rousse, J. Rodríguez-Carvajal, C. Giacobbe, M. Sun, O. Vaccarelli, and G. Radtke
Phys. Rev. B 95, 144103 (2017) - Published 5 April, 2017
Xue Jiang, Xue Wu, Zhaoyang Zheng, Yingying Huang, and Jijun Zhao
Phys. Rev. B 95, 144104 (2017) - Published 6 April, 2017
B. B. L. Witte, M. Shihab, S. H. Glenzer, and R. Redmer
Phys. Rev. B 95, 144105 (2017) - Published 6 April, 2017
P. G. Naumov, K. Filsinger, O. I. Barkalov, G. H. Fecher, S. A. Medvedev, and C. Felser
Phys. Rev. B 95, 144106 (2017) - Published 7 April, 2017
Zebo Li and Dallas R. Trinkle
Phys. Rev. B 95, 144107 (2017) - Published 11 April, 2017
Sankalp Kota, Matthias Agne, Eugenio Zapata-Solvas, Olivier Dezellus, Diego Lopez, Bruno Gardiola, Miladin Radovic, and Michel W. Barsoum
Phys. Rev. B 95, 144108 (2017) - Published 13 April, 2017
F. Shayeganfar, K. S. Vasu, R. R. Nair, F. M. Peeters, and M. Neek-Amal
Phys. Rev. B 95, 144109 (2017) - Published 19 April, 2017
Atsuto Seko, Hiroyuki Hayashi, Keita Nakayama, Akira Takahashi, and Isao Tanaka
Phys. Rev. B 95, 144110 (2017) - Published 19 April, 2017
Guannan Li, Xiaokun Huang, Jingsan Hu, and Weiyi Zhang
Phys. Rev. B 95, 144111 (2017) - Published 19 April, 2017
K. Gautam, D. K. Shukla, S. Francoual, J. Bednarcik, J. R. L. Mardegan, H.-P. Liermann, R. Sankar, F. C. Chou, D. M. Phase, and J. Strempfer
Phys. Rev. B 95, 144112 (2017) - Published 24 April, 2017
Axel van de Walle, Sara Kadkhodaei, Ruoshi Sun, and Qi-Jun Hong
Phys. Rev. B 95, 144113 (2017) - Published 25 April, 2017
M. C. Gregor, D. E. Fratanduono, C. A. McCoy, D. N. Polsin, A. Sorce, J. R. Rygg, G. W. Collins, T. Braun, P. M. Celliers, J. H. Eggert, D. D. Meyerhofer, and T. R. Boehly
Phys. Rev. B 95, 144114 (2017) - Published 26 April, 2017
Bin Xu, Michael Falk, Jinfu Li, and Lingti Kong
Phys. Rev. B 95, 144201 (2017) - Published 12 April, 2017
V. V. Rylkov, S. N. Nikolaev, K. Yu. Chernoglazov, V. A. Demin, A. V. Sitnikov, M. Yu. Presnyakov, A. L. Vasiliev, N. S. Perov, A. S. Vedeneev, Yu. E. Kalinin, V. V. Tugushev, and A. B. Granovsky
Phys. Rev. B 95, 144202 (2017) - Published 12 April, 2017
Xinyang Zhang, Corbyn Mellinger, Eugene V. Colla, M. B. Weissman, and D. D. Viehland
Phys. Rev. B 95, 144203 (2017) - Published 18 April, 2017
Marcel Filoche, Marco Piccardo, Yuh-Renn Wu, Chi-Kang Li, Claude Weisbuch, and Svitlana Mayboroda
Phys. Rev. B 95, 144204 (2017) - Published 18 April, 2017
Marco Piccardo, Chi-Kang Li, Yuh-Renn Wu, James S. Speck, Bastien Bonef, Robert M. Farrell, Marcel Filoche, Lucio Martinelli, Jacques Peretti, and Claude Weisbuch
Phys. Rev. B 95, 144205 (2017) - Published 18 April, 2017
Chi-Kang Li, Marco Piccardo, Li-Shuo Lu, Svitlana Mayboroda, Lucio Martinelli, Jacques Peretti, James S. Speck, Claude Weisbuch, Marcel Filoche, and Yuh-Renn Wu
Phys. Rev. B 95, 144206 (2017) - Published 18 April, 2017
Ofek Asban, Ariel Amir, Yoseph Imry, and Moshe Schechter
Phys. Rev. B 95, 144207 (2017) - Published 20 April, 2017
Y. Zhang, Y. F. Zhang, S. X. Yang, K.-M. Tam, N. S. Vidhyadhiraja, and M. Jarrell
Phys. Rev. B 95, 144208 (2017) - Published 21 April, 2017
Alejandro Mendoza-Coto, Daniel G. Barci, and Daniel A. Stariolo
Phys. Rev. B 95, 144209 (2017) - Published 26 April, 2017
N. Jakse and A. Pasturel
Phys. Rev. B 95, 144210 (2017) - Published 28 April, 2017
Zhao Fan, Jun Ding, Qing-Jie Li, and Evan Ma
Phys. Rev. B 95, 144211 (2017) - Published 28 April, 2017
Emelie Ertan, Victor Kimberg, Faris Gel'mukhanov, Franz Hennies, Jan-Erik Rubensson, Thorsten Schmitt, Vladimir N. Strocov, Kejin Zhou, Marcella Iannuzzi, Alexander Föhlisch, Michael Odelius, and Annette Pietzsch
Phys. Rev. B 95, 144301 (2017) - Published 5 April, 2017
Ronan M. Murphy, Éamonn D. Murray, Stephen Fahy, and Ivana Savić
Phys. Rev. B 95, 144302 (2017) - Published 6 April, 2017
V. Achilleos, G. Theocharis, O. Richoux, and V. Pagneux
Phys. Rev. B 95, 144303 (2017) - Published 10 April, 2017
Utso Bhattacharya, Joanna Hutchinson, and Amit Dutta
Phys. Rev. B 95, 144304 (2017) - Published 11 April, 2017
Bing Li, K. T. Tan, and Johan Christensen
Phys. Rev. B 95, 144305 (2017) - Published 12 April, 2017
Zhedong Zhang, Hongchen Fu, and Jin Wang
Phys. Rev. B 95, 144306 (2017) - Published 12 April, 2017
Galaad Altares Menendez and Bjorn Maes
Phys. Rev. B 95, 144307 (2017) - Published 13 April, 2017
Carlo B. Krimphoff, Masudul Haque, and Andreas M. Läuchli
Phys. Rev. B 95, 144308 (2017) - Published 19 April, 2017
Zheyong Fan, Luiz Felipe C. Pereira, Petri Hirvonen, Mikko M. Ervasti, Ken R. Elder, Davide Donadio, Tapio Ala-Nissila, and Ari Harju
Phys. Rev. B 95, 144309 (2017) - Published 19 April, 2017
Xi Chen, Karalee Jarvis, Sean Sullivan, Yutao Li, Jianshi Zhou, and Li Shi
Phys. Rev. B 95, 144310 (2017) - Published 27 April, 2017
The strong spin-spin exchange interaction in some low-dimensional magnetic materials can give rise to a high group velocity and thermal conductivity contribution from magnons, which are energy quanta of collective spin excitations. Examples are the incommensurate layered compounds (Sr,Ca,La)CuO, with strong antiferromagnetic interaction along the ladders. The effects of grain boundaries and defects on quasi-one-dimensional magnon transport in these compounds are not well understood. Here, the authors report the microstructures and anisotropic thermal transport properties of textured SrCuO. TEM clearly reveals nanolayered grains and the presence of dislocations and planar defects. The thermal conductivity contribution and mean free paths of magnons in the textured samples are evaluated with the use of a kinetic model for one-dimensional magnon transport, and found to be suppressed significantly compared to single crystals at low temperatures. The experimental results can be explained by a one-dimensional magnon-defect scattering model, provided that the magnon–grain boundary scattering mean free path in the anisotropic magnetic structure is smaller than the average length of these nanolayers along the axis. The finding suggests low transmission coefficients for energy-carrying magnons across grain boundaries.
Oindrila Deb and Diptiman Sen
Phys. Rev. B 95, 144311 (2017) - Published 28 April, 2017
Jeroen Mulkers, Bartel Van Waeyenberge, and Milorad V. Milošević
Phys. Rev. B 95, 144401 (2017) - Published 3 April, 2017
So Takei, Yaroslav Tserkovnyak, and Masoud Mohseni
Phys. Rev. B 95, 144402 (2017) - Published 4 April, 2017
Spin Hall phenomena are a collection of relativistic spin-orbit coupling effects that permit control and detection of magnetization dynamics in magnetic materials with electrical currents. In spintronics, they have been studied extensively in bilayer structures consisting of a magnetically ordered material interfaced by a current-carrying paramagnetic metal with strong spin-orbit coupling. In this work, the authors propose the magnetic phase qubit, the macroscopic quantum spintronic device that can be built from such bilayers and that permits full electrical control and readout via spin Hall phenomena. The device is an example of a macroscopic qubit that can be constructed from solid-state materials and so should offer the same advantages as the superconducting qubits of strong inter-qubit coupling and scalability. An estimate of the relevant physical parameters based on current spintronic technology gives a qubit operational temperature that is more than an order of magnitude higher than for existing superconducting qubits, thus opening the possibility of macroscopic quantum information processing at temperatures above the dilution refrigerator range. The authors also show that a coupled array of these qubits can realize a quantum annealer, which could be used to solve certain hard optimization problems and machine learning tasks.
A. Kotani, H. Nakajima, K. Harada, Y. Ishii, and S. Mori
Phys. Rev. B 95, 144403 (2017) - Published 4 April, 2017
Hwanbeom Cho, Marie Kratochvílová, Hasung Sim, Ki-Young Choi, Choong Hyun Kim, Carley Paulsen, Maxim Avdeev, Darren C. Peets, Younghun Jo, Sanghyun Lee, Yukio Noda, Michael J. Lawler, and Je-Geun Park
Phys. Rev. B 95, 144404 (2017) - Published 5 April, 2017
Yunpeng Chen, Halise Celik, Tao Wang, Harsha Kannan, Ilya N. Krivorotov, and John Q. Xiao
Phys. Rev. B 95, 144405 (2017) - Published 7 April, 2017
Kavita Mehlawat, A. Thamizhavel, and Yogesh Singh
Phys. Rev. B 95, 144406 (2017) - Published 7 April, 2017
C. Stock, E. E. Rodriguez, P. Bourges, R. A. Ewings, H. Cao, S. Chi, J. A. Rodriguez-Rivera, and M. A. Green
Phys. Rev. B 95, 144407 (2017) - Published 7 April, 2017
Eirik Løhaugen Fjærbu, Niklas Rohling, and Arne Brataas
Phys. Rev. B 95, 144408 (2017) - Published 10 April, 2017
Jitender Kumar, Soumendra Nath Panja, Deepak John Mukkattukavil, Arpan Bhattacharyya, A. K. Nigam, and Sunil Nair
Phys. Rev. B 95, 144409 (2017) - Published 10 April, 2017
Alexey Peretyatko, Konstantin Nefedev, and Yutaka Okabe
Phys. Rev. B 95, 144410 (2017) - Published 11 April, 2017
S. Shihab, L. Thevenard, A. Lemaître, and C. Gourdon
Phys. Rev. B 95, 144411 (2017) - Published 12 April, 2017
In ferromagnetic layers, spin-wave modes can be excited by a laser pulse launching the magnetization out of equilibrium and into precession. The trajectory of the magnetization vector can be fully reconstructed using different magneto-optical effects, generally admitted to give a faithful picture of the dynamics. The authors show that this is not always the case and that magneto-optical effects can indeed be deceiving. For this, they study the case of a weakly absorbing ferromagnet, the semiconductor GaMnAs, in which perpendicular standing spin waves are excited by a laser pulse. Quite counterintuitively, the optical detection shows the first two excited modes to be of opposite chirality, whereas theory tells us the spin waves actually rotate in the same direction. The paper demonstrates that this unexpected and surprising effect is a pure optical illusion. It can perfectly be explained by taking into account absorption and optical phase shift inside the layer, the latter being particularly strong in weakly absorbing layers. These results provide a correct identification of spin-wave modes, enabling a trustworthy estimation of their respective weight as well as an unambiguous determination of the spin stiffness parameter.
James Turtle, Pietro-Luciano Buono, Antonio Palacios, Christine Dabrowski, Visarath In, and Patrick Longhini
Phys. Rev. B 95, 144412 (2017) - Published 12 April, 2017
Po-Hao Huang, Jyong-Hao Chen, Adrian E. Feiguin, Claudio Chamon, and Christopher Mudry
Phys. Rev. B 95, 144413 (2017) - Published 12 April, 2017
K. A. Ross, J. M. Brown, R. J. Cava, J. W. Krizan, S. E. Nagler, J. A. Rodriguez-Rivera, and M. B. Stone
Phys. Rev. B 95, 144414 (2017) - Published 13 April, 2017
Quantum effects in magnetic materials are prevalent when the magnetic ions support spin-½ moments, as in Cu-based materials. Strong quantum effects can also be achieved when the large angular momentum states are reduced to an effective spin-½ subspace (=½) by the combined effect of spin-orbit coupling and the crystal electric field. A consequence of this is the introduction of anisotropy to the g tensor and the effective exchange interactions. Such anisotropic =½ models have recently been applied successfully to rare-earth based frustrated pyrochlore materials, where they are found to lead to particularly rich phenomenology for XY-like tensors. Here, it is shown that a similar quantum model should apply to the recently discovered “high temperature” Co pyrochlores, NaCaCoF and NaSrCoF, based on a fit to their single ion levels as measured via inelastic neutron scattering. The effect of the intrinsic crystalline disorder on the anisotropy of the =½ moments in these materials is also estimated.
Alexandros Metavitsiadis and Sebastian Eggert
Phys. Rev. B 95, 144415 (2017) - Published 13 April, 2017
Robert D. Fraleigh, Susan Kempinger, Paul E. Lammert, Sheng Zhang, Vincent H. Crespi, Peter Schiffer, and Nitin Samarth
Phys. Rev. B 95, 144416 (2017) - Published 13 April, 2017
A. F. Franco, C. Gonzalez-Fuentes, J. Åkerman, and C. Garcia
Phys. Rev. B 95, 144417 (2017) - Published 14 April, 2017
E. T. Dias, K. R. Priolkar, A. K. Nigam, R. Singh, A. Das, and G. Aquilanti
Phys. Rev. B 95, 144418 (2017) - Published 14 April, 2017
Abbey J. Neer, JoAnna Milam-Guerrero, Justin E. So, Brent C. Melot, Kate A. Ross, Zeric Hulvey, Craig M. Brown, Alexey A. Sokol, and David O. Scanlon
Phys. Rev. B 95, 144419 (2017) - Published 14 April, 2017
Benedetta Flebus, Ka Shen, Takashi Kikkawa, Ken-ichi Uchida, Zhiyong Qiu, Eiji Saitoh, Rembert A. Duine, and Gerrit E. W. Bauer
Phys. Rev. B 95, 144420 (2017) - Published 14 April, 2017
Michael A. McGuire, V. Ovidiu Garlea, Santosh KC, Valentino R. Cooper, Jiaqiang Yan, Huibo Cao, and Brian C. Sales
Phys. Rev. B 95, 144421 (2017) - Published 14 April, 2017
Ji-Wan Kim and Jean-Yves Bigot
Phys. Rev. B 95, 144422 (2017) - Published 17 April, 2017
Muftah Al-Mahdawi, Satya Prakash Pati, Yohei Shiokawa, Shujun Ye, Tomohiro Nozaki, and Masashi Sahashi
Phys. Rev. B 95, 144423 (2017) - Published 17 April, 2017
Vladimir A. Gavrichkov, Semen I. Polukeev, and Sergey G. Ovchinnikov
Phys. Rev. B 95, 144424 (2017) - Published 17 April, 2017
Haoyu Wang, Hitesh J. Changlani, Yuan Wan, and Oleg Tchernyshyov
Phys. Rev. B 95, 144425 (2017) - Published 18 April, 2017
M. Zhu, J. Peng, W. Tian, T. Hong, Z. Q. Mao, and X. Ke
Phys. Rev. B 95, 144426 (2017) - Published 21 April, 2017
Gia-Wei Chern, Yuriy Sizyuk, Craig Price, and Natalia B. Perkins
Phys. Rev. B 95, 144427 (2017) - Published 21 April, 2017
Yong-Liang Dong, Lei Chen, Yun-Jing Liu, and Wei Li
Phys. Rev. B 95, 144428 (2017) - Published 24 April, 2017
Masashi Hase, Yuta Ebukuro, Haruhiko Kuroe, Masashige Matsumoto, Akira Matsuo, Koichi Kindo, James R. Hester, Taku J. Sato, and Hiroki Yamazaki
Phys. Rev. B 95, 144429 (2017) - Published 24 April, 2017
A. N. Ribeiro and N. S. Ferreira
Phys. Rev. B 95, 144430 (2017) - Published 27 April, 2017
O. Perevertov, O. Heczko, and R. Schäfer
Phys. Rev. B 95, 144431 (2017) - Published 27 April, 2017
E. B. Sonin
Phys. Rev. B 95, 144432 (2017) - Published 27 April, 2017
Recently, it was suggested that metastable spin supercurrents (spin superfluidity) are possible in the magnon condensate observed in yttrium iron garnet (YIG) magnetic films under strong magnon pumping. In YIG, magnetic anisotropy is rather weak, and this material can be treated as an isotropic ferromagnet. Its order-parameter space is a sphere of radius equal to the spontaneous magnetization . A current state maps on the equatorial circumference on the sphere, and topology of the sphere allows us to continuously transform the equatorial circumference to the point. This rules out metastable current states. Only easy-plane anisotropy reducing the order-parameter space from the sphere to the equatorial circumference makes current states topologically stable. However, by pumping magnons to the isotropic ferromagnet in a magnetic field, it is possible to support a strongly nonequilibrium state with fixed average . This confines the precessing spin to an “easy plane” of dynamical rather than topological origin and makes metastable spin currents possible. But final judgment requires evaluation of the Landau superfluidity criterion as done in the present work. The conclusion is that spin superfluidity in YIG films is possible in principle, although the recently published claim of its observation is not justified.
L. J. Bannenberg, K. Kakurai, P. Falus, E. Lelièvre-Berna, R. Dalgliesh, C. D. Dewhurst, F. Qian, Y. Onose, Y. Endoh, Y. Tokura, and C. Pappas
Phys. Rev. B 95, 144433 (2017) - Published 28 April, 2017
Chiral magnetism plays an increasingly important role in condensed matter investigations driven by the discovery of exotic spin textures, such as the topologically protected chiral skyrmions that can form a lattice under magnetic fields. The nature and universality of the phase diagram in cubic chiral magnets has been the subject of numerous experimental and theoretical investigations, including the transition to the helimagnetic state. In MnSi, the archetypal system in this family, this transition is of first order and involves a precursor phase, where strong chiral fluctuating correlations build up. This work presents an experimental investigation of the structural and dynamical aspects of the phase transition in FeCoSi, a system that belongs to the same family as MnSi but with the additional possibility to tune important physical interactions and parameters through variation of the Fe and Co concentration. In this system, the combination of small-angle neutron scattering and neutron spin echo spectroscopy uncovers that the scenario of the transition is qualitatively very different from that in MnSi. This goes beyond what can be expected from a comparison of the relevant length scales and thus challenges the validity of a universal approach to the helimagnetic transition in cubic chiral magnets.
T. Flottat, L. de Forges de Parny, F. Hébert, V. G. Rousseau, and G. G. Batrouni
Phys. Rev. B 95, 144501 (2017) - Published 3 April, 2017
Susumu Katano, Kohei Shibata, Kotaro Nakashima, and Yohei Matsubara
Phys. Rev. B 95, 144502 (2017) - Published 3 April, 2017
Sayed Ali Akbar Ghorashi, Seth Davis, and Matthew S. Foster
Phys. Rev. B 95, 144503 (2017) - Published 3 April, 2017
V. K. Vlasko-Vlasov, F. Colauto, A. I. Buzdin, D. Rosenmann, T. Benseman, and W.-K. Kwok
Phys. Rev. B 95, 144504 (2017) - Published 4 April, 2017
A. J. S. Machado, N. P. Baptista, B. S. de Lima, N. Chaia, T. W. Grant, L. E. Corrêa, S. T. Renosto, A. C. Scaramussa, R. F. Jardim, M. S. Torikachvili, J. Albino Aguiar, O. C. Cigarroa, L. T. F. Eleno, and Z. Fisk
Phys. Rev. B 95, 144505 (2017) - Published 4 April, 2017
J. Khatibi Moqadam, M. C. de Oliveira, and R. Portugal
Phys. Rev. B 95, 144506 (2017) - Published 5 April, 2017
Wan-Sheng Wang, Miao Gao, Yang Yang, Yuan-Yuan Xiang, and Qiang-Hua Wang
Phys. Rev. B 95, 144507 (2017) - Published 17 April, 2017
Evan Sosenko, Junhua Zhang, and Vivek Aji
Phys. Rev. B 95, 144508 (2017) - Published 18 April, 2017
M. S. Bryan, T. R. Prisk, T. E. Sherline, S. O. Diallo, and P. E. Sokol
Phys. Rev. B 95, 144509 (2017) - Published 20 April, 2017
Shai Wissberg and Beena Kalisky
Phys. Rev. B 95, 144510 (2017) - Published 20 April, 2017
L. Fanfarillo, G. Giovannetti, M. Capone, and E. Bascones
Phys. Rev. B 95, 144511 (2017) - Published 24 April, 2017
P. Virtanen, P. Solinas, and F. Giazotto
Phys. Rev. B 95, 144512 (2017) - Published 24 April, 2017
J. Fink, E. D. L. Rienks, S. Thirupathaiah, J. Nayak, A. van Roekeghem, S. Biermann, T. Wolf, P. Adelmann, H. S. Jeevan, P. Gegenwart, S. Wurmehl, C. Felser, and B. Büchner
Phys. Rev. B 95, 144513 (2017) - Published 25 April, 2017
Zh. Devizorova and S. Mironov
Phys. Rev. B 95, 144514 (2017) - Published 26 April, 2017
Jacob Linder and Takehito Yokoyama
Phys. Rev. B 95, 144515 (2017) - Published 26 April, 2017
E. Schachinger and J. P. Carbotte
Phys. Rev. B 95, 144516 (2017) - Published 27 April, 2017