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Research

Publications:

The most important scientific results

Magnetoelastic interactions between spin waves and surface acoustic waves (2018-2020)

In planar magnonic systems placed on an elastic substrate, the interaction between spin waves and surface acoustic waves is possible. We have shown that in the case of a homogeneous magnetic layer, its thickness can be important for observing the interaction of a Rayleigh wave with a spin wave. We have also shown that the localization of the spin wave in a one-dimensional planar magnonic crystal changes the anisotropy of the magnetoelastic interaction, which is related to the orientation of the magnetic field with respect to the direction of the wave vector [1, 2].

Theory of surface states and interface states in magnonic crystals (2013-2017)

In periodic nanostructures, the surfaces and the structural defects break the translational symmetry of the system. It leads to the appearance of the localized states of the frequencies in the ranges forbidden for propagating modes. In our studies, we investigated the 1D magnonic crystals with surfaces introduced in symmetry points or defects interfacing with the unperturbed sections of magnonic crystals at symmetry points. Such an approach allows introducing the symmetry-related criterion of existence of magnonic surface/defect modes [3, 4, 5].

Spin waves in planar 2D magnonic crystal and periodic magnonic waveguides (2013-2015)

Planar magnonic crystals and planar periodic waveguides are the most common experimental realizations of periodic magnonic nanostructures. The spin wave propagation in this system depends not only on the geometry but also on the magnetic configuration, which can be tailored by the application of a magnetic field. We have performed various theoretical and numerical studies to investigate the effect of the structural parameters and external bias on the spin wave spectrum, considering both the short-range (exchange) and long-range (dipolar) interactions [6, 7, 8].

Electronic transport in graphene nanoribbons (2009-2010)

We studied teoretically and numerically the impact of charged impurities (in the substrate) and the ripples in the graphene layer on the electron density n and transport characteristics (conductivity σ, mobility, mean-free-path) in crossover dipolar-diffusive regime. We showed that the transition from the ballistic regime to the diffusive regime is manifested by the change of the power-low dependence σ~nγ, with the exponent γ ranging from 0.5 to 1. This finding questions the applicability of the standard Boltzmann approach within the Born approximation [9, 10]

Determination of the ultimate efficiency for the intermediate band solar cells (2009)

We have demonstrated numerically that 2D AlGaAs/GaAs superlattices can be used to design the system where the lowest electronic miniband plays the role of an intermediate band for the electron/hole transition. We have shown that such a nanostructure is characterized by a significant increase in the ultimate (quantum) efficiency of photovoltaic energy conversion [11]).

Selected papers

1. N. K. P.Babu, A. Trzaskowska, P. Graczyk, G. Centała, S. Mieszczak, H. Głowiński, M. Zdunek, S. Mielcarek, J. W. Kłos, The Interaction between Surface Acoustic Waves and Spin Waves: The Role of Anisotropy and Spatial Profiles of the Modes, Nano Letters 21, 946 (2021), DOI:10.1021/acs.nanolett.0c03692

2. C. L. Chang, S. Mieszczak, M. Zelent, V. Besse, U. Martens, R. R. Tamming, J. Janusonis, P. Graczyk, M. Münzenberg, J. W. Kłos, R. I. Tobey, Driving magnetization dynamics in an on-demand magnonic crystal via the magnetoelastic interactions, Phys. Rev. Applied 10, 064051 (2018), DOI:10.1103/PhysRevApplied.10.064051

3. P. Graczyk, J. Kłos, M. Krawczyk, Broadband magnetoelastic coupling in magnonic-phononic crystals for high-frequency nanoscale spin-wave generation, Phys. Rev. B 95, 104425 (2017), DOI: PhysRevB.95.104425

4. J. Rychły, J. W. Kłos, M. Mruczkiewicz, M. Krawczyk, Spin waves in one-dimensional bicomponent magnonic quasicrystals, Phys. Rev. B 92, 054414 (2015), DOI:10.1103/PhysRevB.92.054414

5. J. W Kłos, M. Krawczyk, Y.S. Dadoenkova, N.N. Dadoenkova, I.L. Lyubchanskii, Photonic-magnonic crystals: Multifunctional periodic structures for magnonic and photonic applications, J. Appl. Phys. 115, 174311 (2014), DOI:10.1063/1.4874797

6. J. W. Kłos, D. Kumar, M. Krawczyk, A. Barman, Magnonic band engineering by intrinsic and extrinsic mirror symmetry breaking in antidot spin-wave waveguides, Sci. Rep. 3, 2444 (2013), DOI:10.1038/srep02444

7. J. W. Kłos, M. L. Sokolovskyy, S. Mamica, M. Krawczyk, The impact of the lattice symmetry and the inclusion shape on the spectrum of 2D magnonic crystals, J. Appl. Phys. 111 , 123910 (2012), DOI:10.1063/1.4729559

8. M. Koralewski, J. W. Kłos, M. Baranowski, Z. Mitróová, P. Kopčanský, L. Melníková, M. Okuda, W. Schwarzacher, The Faraday effect of natural and artificial ferritins , Nanotechnology 23 , 355704 (2012), DOI:10.1088/0957-4484/23/35/355704

9. J. W. Kłos, I. V. Zozoulenko, Effect of short-and long-range scattering on the conductivity of graphene: Boltzmann approach vs tight-binding calculations, Phys. Rev. B 82, 081414 (2010), DOI:10.1103/PhysRevB.82.081414

10. J. W Kłos, M. Krawczyk, Two-dimensional GaAs/AlGaAs superlattice structures for solar cell applications: Ultimate efficiency estimation, J. Appl. Phys. 106, 093703 (2009), DOI:10.1063/1.3253584

Grants(PI)

  1. The studies on of electronic spectrum of low-dimensional semiconductor heterostructures useful in designing solar cells, 23.10.2007-22.10.2009, KBN (N N507 3318 33)
  2. Spin separation of electronic states in the regime of quantum Hall effect in quantum antidots and wires, 22.09.2008-21.09.2009, Ministry of Sicence and Higer Education (213/MOB/2008/0)
  3. Modification of the interactions between magnons and phonons in periodic nanostructures by adjusting the structural and material parameters, 06.02.2017-05.03.2021, NCN (OPUS, 2016/21/B/ST3/00452)
  4. Spin waves in hybrid nanostructures – the role of surface anisotropy, NCN (PRELUDUM-BIS, 2020/39/O/ST5/02110)
  5. Low-loss current- and flux quanta-controlled magnonics, approved for financing, 01.02.2023-01.02.2026 NCN (OPUS-LAP, 2021/43/I/ST3/00550)

Promoted PhDs

  1. Justyna Rychły, PhD thesis: Localization properties of spin waves in planar magnonic crystals and quasicrystals, 2019
  2. Szymon Mieszczak, PhD thesis: Spin waves in magnonic systems: localization and propagation, 2022