The Experts below are selected from a list of 9876 Experts worldwide ranked by ideXlab platform
Oppeneer, Peter M. - One of the best experts on this subject based on the ideXlab platform.
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Influence of intersublattice coupling on the terahertz nutation spin dynamics in antiferromagnets
'American Physical Society (APS)', 2021Co-Authors: Mondal Ritwik, Oppeneer, Peter M.Abstract:Spin-nutation resonance has been well explored in one-sublattice ferromagnets. Here, we investigate the spin nutation in two-sublattice antiferromagnets as well as, for comparison, ferrimagnets with inter- and intrasublattice nutation coupling. In particular, we derive the susceptibility of the two-sublattice magnetic system in response to an applied external magnetic field. To this end, the antiferromagnetic and ferrimagnetic (sub-THz) precession and THz nutation resonance frequencies are calculated. Our results show that the precession resonance frequencies and effective Damping Decrease with intrasublattic nutation coupling, while they increase with intersublattice nutation in an antiferromagnet. However, we find that the THz nutation resonance frequencies Decrease with both the intra- and intersublattice nutation couplings. For ferrimagnets, conversely, we calculate two nutation modes with distinct frequencies, unlike antiferromagnets. The exchangelike precession resonance frequency of ferrimagnets Decreases with intrasublattice nutation coupling and increases with intersublattice nutation coupling, as antiferromagnets, but the ferromagneticlike precession frequency of ferrimagnets is practically invariant to the intra- and intersublattice nutation couplings
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Influence of inter-sublattice coupling on the terahertz nutation spin dynamics in antiferromagnets
2021Co-Authors: Mondal Ritwik, Oppeneer, Peter M.Abstract:Spin nutation resonance has been well-explored in one-sublattice ferromagnets. Here, we investigate the spin nutation in two-sublattice antiferromagnets as well as, for comparison, ferrimagnets with inter-and intra-sublattice nutation coupling. In particular, we derive the susceptibility of the two-sublattice magnetic system in response to an applied external magnetic field. To this end, the antiferromagnetic and ferrimagnetic (sub-THz) precession and THz nutation resonance frequencies are calculated. Our results show that the precession resonance frequencies and effective Damping Decrease with intra-sublattice nutation coupling, while they increase with inter -sublattice nutation in an antiferromagnet. However, we find that the THz nutation resonance frequencies Decrease with both the intra-and inter-sublattice nutation couplings. For ferrimagnets, conversely, we calculate two nutation modes with distinct frequencies, unlike antiferromagnets. The exchange-like precession resonance frequency of ferrimagnets Decreases with intra-sublattice nutation coupling and increases with inter-sublattice nutation coupling, like antiferromagnets, but the ferromagnetic-like precession frequency of ferrimagnets is practically invariant to the intra and inter-sublattice nutation couplings.Comment: 8 pages, 5 figure
Mondal Ritwik - One of the best experts on this subject based on the ideXlab platform.
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Influence of intersublattice coupling on the terahertz nutation spin dynamics in antiferromagnets
'American Physical Society (APS)', 2021Co-Authors: Mondal Ritwik, Oppeneer, Peter M.Abstract:Spin-nutation resonance has been well explored in one-sublattice ferromagnets. Here, we investigate the spin nutation in two-sublattice antiferromagnets as well as, for comparison, ferrimagnets with inter- and intrasublattice nutation coupling. In particular, we derive the susceptibility of the two-sublattice magnetic system in response to an applied external magnetic field. To this end, the antiferromagnetic and ferrimagnetic (sub-THz) precession and THz nutation resonance frequencies are calculated. Our results show that the precession resonance frequencies and effective Damping Decrease with intrasublattic nutation coupling, while they increase with intersublattice nutation in an antiferromagnet. However, we find that the THz nutation resonance frequencies Decrease with both the intra- and intersublattice nutation couplings. For ferrimagnets, conversely, we calculate two nutation modes with distinct frequencies, unlike antiferromagnets. The exchangelike precession resonance frequency of ferrimagnets Decreases with intrasublattice nutation coupling and increases with intersublattice nutation coupling, as antiferromagnets, but the ferromagneticlike precession frequency of ferrimagnets is practically invariant to the intra- and intersublattice nutation couplings
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Influence of inter-sublattice coupling on the terahertz nutation spin dynamics in antiferromagnets
2021Co-Authors: Mondal Ritwik, Oppeneer, Peter M.Abstract:Spin nutation resonance has been well-explored in one-sublattice ferromagnets. Here, we investigate the spin nutation in two-sublattice antiferromagnets as well as, for comparison, ferrimagnets with inter-and intra-sublattice nutation coupling. In particular, we derive the susceptibility of the two-sublattice magnetic system in response to an applied external magnetic field. To this end, the antiferromagnetic and ferrimagnetic (sub-THz) precession and THz nutation resonance frequencies are calculated. Our results show that the precession resonance frequencies and effective Damping Decrease with intra-sublattice nutation coupling, while they increase with inter -sublattice nutation in an antiferromagnet. However, we find that the THz nutation resonance frequencies Decrease with both the intra-and inter-sublattice nutation couplings. For ferrimagnets, conversely, we calculate two nutation modes with distinct frequencies, unlike antiferromagnets. The exchange-like precession resonance frequency of ferrimagnets Decreases with intra-sublattice nutation coupling and increases with inter-sublattice nutation coupling, like antiferromagnets, but the ferromagnetic-like precession frequency of ferrimagnets is practically invariant to the intra and inter-sublattice nutation couplings.Comment: 8 pages, 5 figure
Bingyong Guo - One of the best experts on this subject based on the ideXlab platform.
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enhancement of wave energy absorption efficiency via geometry and power take off Damping tuning
Energy, 2019Co-Authors: Siya Jin, Ron J Patton, Bingyong GuoAbstract:Abstract In this work a three dimensional computational fluid dynamic (CFD) model has been constructed based on a 1/50 scale heaving point absorber wave energy converter (PAWEC). The CFD model is validated first via wave tank tests and then is applied in this study to investigate the joint effects of device geometry and power take-off (PTO) Damping on wave energy absorption. Three PAWEC devices are studied with the following geometrical designs: a cylindrical flat-bottom device (CL); a hemispherical streamlined bottom design (CH) and a 90°-conical streamlined bottom structure (CC). A PTO force via varying Damping coefficient is applied to compare the power conversion performances of the aforementioned devices. Free decay, wave-PAWEC interaction and power absorption tests are conducted via the CFD model. The results show that for CH and CC designs the added mass and hydrodynamic Damping Decrease by up to 60% compared with the CL device. Moreover, the CC design is the best of the three structures since its amplitude response increases by up to 100% compared with the CL. Applying an appropriate PTO Damping to the CC device prominently increases the achievable optimal power by up to 70% under both regular and irregular waves (compared with the CL device).
Siya Jin - One of the best experts on this subject based on the ideXlab platform.
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enhancement of wave energy absorption efficiency via geometry and power take off Damping tuning
Energy, 2019Co-Authors: Siya Jin, Ron J Patton, Bingyong GuoAbstract:Abstract In this work a three dimensional computational fluid dynamic (CFD) model has been constructed based on a 1/50 scale heaving point absorber wave energy converter (PAWEC). The CFD model is validated first via wave tank tests and then is applied in this study to investigate the joint effects of device geometry and power take-off (PTO) Damping on wave energy absorption. Three PAWEC devices are studied with the following geometrical designs: a cylindrical flat-bottom device (CL); a hemispherical streamlined bottom design (CH) and a 90°-conical streamlined bottom structure (CC). A PTO force via varying Damping coefficient is applied to compare the power conversion performances of the aforementioned devices. Free decay, wave-PAWEC interaction and power absorption tests are conducted via the CFD model. The results show that for CH and CC designs the added mass and hydrodynamic Damping Decrease by up to 60% compared with the CL device. Moreover, the CC design is the best of the three structures since its amplitude response increases by up to 100% compared with the CL. Applying an appropriate PTO Damping to the CC device prominently increases the achievable optimal power by up to 70% under both regular and irregular waves (compared with the CL device).
Ron J Patton - One of the best experts on this subject based on the ideXlab platform.
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enhancement of wave energy absorption efficiency via geometry and power take off Damping tuning
Energy, 2019Co-Authors: Siya Jin, Ron J Patton, Bingyong GuoAbstract:Abstract In this work a three dimensional computational fluid dynamic (CFD) model has been constructed based on a 1/50 scale heaving point absorber wave energy converter (PAWEC). The CFD model is validated first via wave tank tests and then is applied in this study to investigate the joint effects of device geometry and power take-off (PTO) Damping on wave energy absorption. Three PAWEC devices are studied with the following geometrical designs: a cylindrical flat-bottom device (CL); a hemispherical streamlined bottom design (CH) and a 90°-conical streamlined bottom structure (CC). A PTO force via varying Damping coefficient is applied to compare the power conversion performances of the aforementioned devices. Free decay, wave-PAWEC interaction and power absorption tests are conducted via the CFD model. The results show that for CH and CC designs the added mass and hydrodynamic Damping Decrease by up to 60% compared with the CL device. Moreover, the CC design is the best of the three structures since its amplitude response increases by up to 100% compared with the CL. Applying an appropriate PTO Damping to the CC device prominently increases the achievable optimal power by up to 70% under both regular and irregular waves (compared with the CL device).
