Spindynamik und Magnetismus von frustrierten Spinsystemen
Zusammenfassung der Projektergebnisse
1. We studied magnetic properties of a quantum spin ladder CPPP in proximity to the isotropic limit. Remarkably, no sign of magnetic ordering was observed in the fieldinduced phase down to 40 mK. 2. We published a review article on the spin dynamics in quantum sine-Gordon chains, studied with high-field ESR studies. 3. We studied high-field spin-flop transition in the natural mineral green dioptase. The observations are described taking into account structural peculiarities of this material. 4. We performed ESR in in the molecular-based magnet CuPOF, allowing us to obtain important information on the spin-Hamiltonian parameters of this quasi-two-dimensional material. 5. Using high-field ESR technique, we observed several magnon modes in the honeycomblattice material α-RuCl3. This observation allowed us to make important statement about the nature of the elementary excitations in this frustrated material. 6. We studied the spin-dimer ground state in the anionic mixed-valence compound Rb4O6, which is driven by consecutive charge and orbital ordering transitions. 7. ESR was used to study of spin relaxation in the strong-leg spin ladder DIMPY with nonmagnetic dilution. 8. We studied low-temperature thermal conductivity of the spin-1/2 triangular-lattice Cs2CuCl4. Based on that, the one-dimensional nature of magnetic correlations was revealed in this frustrated material, in spite of its two-dimensional triangular structure. 9. We studied one- and three-dimensional quantum phase transitions and anisotropy in frustrated spin system Rb2Cu2Mo3O12. 10. We observed the 2/3 magnetization plateau in a frustrated S=1 isolated spin-triangle compound. The plateau was suggested to be as a remarkable result of the interplay between Heisenberg and biquadratic exchange interactions. 11. We studied magnetic structure and spin waves in the frustrated ferro-antiferromagnet Pb2VO(PO4)2. 12. We proposed a new approach, allowing not only to quasi-continuously tune the exchange parameters by hydrostatic pressure in spin systems with triangular lattice and staggered Dzyaloshinskii-Moriya interaction, but also to accurately monitor them. The approach was used for Cs2CuCl4, open a new direction for investigating quantum spin systems. Moreover, a number of new field-induced transitions were observed in the high-pressure phase, whose detailed interpretation remains open question. 13. We studied magnetic properties and quantum criticality in the coupled two-leg spin ladder Ba2CuTeO6. 14. We studied low-temperature magnetic structure and magnetic properties of the quasione-dimensional S=1/2 Heisenberg helimagnet CuCl2⋅2NC5H5.
Projektbezogene Publikationen (Auswahl)
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Low-temperature magnetic structure and electron paramagnetic resonance properties of the quasi-one-dimensional S=1/2 Heisenberg helimagnet CuCl2⋅2NC5H5, Phys. Rev. B 95, 195125 (2017)
A. N. Ponomaryov, L. Zviagina, J. Wosnitza, M. Thede, E. Ressouche, K. Yu. Povarov, A. Zheludev, C. P. Landee, and S. A. Zvyagin
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Unconventional spin dynamics in the honeycomb-lattice material α−RuCl3: High-field electron spin resonance studies, Phys. Rev. B 96, 241107(R) (2017)
A. N. Ponomaryov, E. Schulze, J. Wosnitza, P. Lampen-Kelley, A. Banerjee, J.-Q. Yan, C. A. Bridges, D. G. Mandrus, S. E. Nagler, A. K. Kolezhuk, and S. A. Zvyagin
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Evidence of one-dimensional magnetic heat transport in the triangular-lattice antiferromagnet Cs2CuCl4, Phys. Rev. Res. 1, 032022 (2019)
E. Schulze, S. Arsenijevic, L. Opherden, A. N. Ponomaryov, J. Wosnitza, T. Ono, H. Tanaka, and S. A. Zvyagin
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Pressure-tuning the quantum spin Hamiltonian of the triangular lattice antiferromagnet Cs2CuCl4, Nat. Comm. 10, 1064 (2019)
S.A. Zvyagin, D. Graf, T. Sakurai, S. Kimura, H. Nojiri, J. Wosnitza, H. Ohta, T. Ono, and H. Tanaka
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Extremely well isolated two-dimensional spin- 1/2 antiferromagnetic Heisenberg layers with a small exchange coupling in the molecular-based magnet CuPOF, Phys. Rev. B 102, 064431 (2020)
D. Opherden, N. Nizar, K. Richardson, J. C. Monroe, M. M. Turnbull, M. Polson, S. Vela, W. J. A. Blackmore, P. A. Goddard, J. Singleton, E. S. Choi, F. Xiao, R. C. Williams, T. Lancaster, F. L. Pratt, S. J. Blundell, Y. Skourski, M. Uhlarz, A. N. Ponomaryov, S. A. Zvyagin, J. Wosnitza, M. Baenitz, I. Heinmaa, R. Stern, H. Kühne, and C. P. Landee
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Nature of Magnetic Excitations in the High-Field Phase of α-RuCl3, Phys. Rev. Lett. 125, 037202 (2020)
Ponomaryov, L. Zviagina, J. Wosnitza, P. Lampen-Kelley, A. Banerjee, J.-Q. Yan, C. A. Bridges, D. G. Mandrus, S. E. Nagler, and S. A. Zvyagin
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Magnetic properties of a quantum spin ladder in proximity to the isotropic limit, Phys. Rev. B 103, 205131 (2021)
S. A. Zvyagin, A. N. Ponomaryov, M. Ozerov, E. Schulze, Y. Skourski, R. Beyer, T. Reimann , L. I. Zviagina, E. L. Green, J. Wosnitza, I. Sheikin, P. Bouillot, T. Giamarchi, J. L. Wikara, M. M. Turnbull , and C. P. Landee
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Spin dynamics in quantum sine-Gordon chains: high-field ESR studies, Appl. Magn. Res. 52, 337 (2021)
S.A. Zvyagin
