Publications de Vinayak Shantaram Bhat

Periodic and Aperiodic NiFe Nanomagnet/Ferrimagnet Hybrid Structures for 2D Magnon Steering and Interferometry with High Extinction Ratio

Dirk Grundler, Vinayak Shantaram Bhat, Sho Watanabe, Andrea Mucchietto, Shixuan Shan, Elif Nur Dayi

Magnons, quanta of spin waves, are known to enable information processing with low power consumption at the nanoscale. So far, however, experimentally realized half-adders, wave-logic and binary output operations were based on few µm-long spin waves and re ...

Wiley2023

Periodic and aperiodic NiFe nanomagnet/ferrimagnet hybrid structures for 2D magnon steering and interferometry with high extinction ratio

Dirk Grundler, Vinayak Shantaram Bhat, Sho Watanabe, Andrea Mucchietto, Shixuan Shan, Elif Nur Dayi

File formats are described in read_me files in the concerning folder. For plotting and data evaluation, Python 2.7 was used. Example scripts for plotting are provided. ...

Zenodo2023

Spin dynamics, loop formation and cooperative reversal in artificial quasicrystals with tailored exchange coupling

Dirk Grundler, Vinayak Shantaram Bhat, Sho Watanabe

Aperiodicity and un-conventional rotational symmetries allow quasicrystalline structures to exhibit unusual physical and functional properties. In magnetism, artificial ferromagnetic quasicrystals exhibited knee anomalies suggesting reprogrammable magnetic ...

2023

Tuning interactions in reconfigurable kagome artificial spin ices for magnonics

Dirk Grundler, Vinayak Shantaram Bhat

We report broadband spin-wave spectroscopy on kagome artificial spin ices (KASIs) made of large arrays of disconnected Ni81Fe19 400-nm-long nanobars. We observed spin wave spectra that varied characteristically upon the separation between neighboring nanob ...

AIP American Institute of Physics2021

Direct observation of multiband transport in magnonic Penrose quasicrystals via broadband and phase-resolved spectroscopy

Dirk Grundler, Korbinian Baumgärtl, Vinayak Shantaram Bhat, Sho Watanabe, Mohammad Hamdi

Quasicrystals are aperiodically ordered structures with unconventional rotational symmetry. Their peculiar features have been explored in photonics to engineer bandgaps for light waves. Magnons (spin waves) are collective spin excitations in magnetically o ...

2021

Direct Observation of Worm‐Like Nanochannels and Emergent Magnon Motifs in Artificial Ferromagnetic Quasicrystals

Dirk Grundler, Vinayak Shantaram Bhat, Sho Watanabe

Quasicrystalline structures and aperiodic metamaterials find applications ranging from established consumer gadgets to potential high‐tech photonic components owing to both complex arrangements of constituents and exotic rotational symmetries. Magnonics is ...

2020

Magnon Modes of Microstates and Microwave-Induced Avalanche in Kagome Artificial Spin Ice with Topological Defects

Dirk Grundler, Vinayak Shantaram Bhat

We investigate spin dynamics of microstates in artificial spin ice (ASI) in Ni81Fe19 nanomagnets arranged in an interconnected kagome lattice using microfocus Brillouin light scattering, broadband ferromagnetic resonance, magnetic force microscopy, x-ray p ...

2020

Optimization of Spin-Wave Propagation with Enhanced Group Velocities by Exchange-Coupled Ferrimagnet-Ferromagnet Bilayers

Dirk Grundler, Vinayak Shantaram Bhat, Kyongmo An

We report broadband spectroscopy and numerical analysis by which we explore propagating spin waves in a magnetic bilayer consisting of a 23-nm thick permalloy film deposited on 130-nm thick Y_3Fe_5O_12. In the bilayer, we observe a characteristic mode that ...

American Physical Society (APS)2019

Angle-dependent magnetization dynamics with mirror-symmetric excitations in artificial quasicrystalline nanomagnet lattices

Dirk Grundler, Vinayak Shantaram Bhat

We report angle-dependent spin-wave spectroscopy on aperiodic quasicrystalline magnetic lattices, i.e., Ammann, Penrose P2 and P3 lattices made of large arrays of interconnected Ni80Fe20 nanobars. Spin-wave spectra obtained in the nearly saturated state co ...

2018

Angular-dependent magnetization dynamics of kagome artificial spin ice incorporating topological defects

Dirk Grundler, Vinayak Shantaram Bhat

We report angular-dependent spin-wave spectroscopy on kagome artificial spin ice made of large arrays of interconnected Ni80Fe20 nanobars. Spectra taken in saturated and disordered states exhibit a series of resonances with characteristic in-plane angular ...

Amer Physical Soc2017

Magnetization dynamics of topological defects and the spin solid in a kagome artificial spin ice

Dirk Grundler, Vinayak Shantaram Bhat

We report broadband spin-wave spectroscopy on kagome artificial spin ice (ASI) made of large arrays of interconnected Ni 80 Fe 20 nanobars. Spectra taken in saturated and disordered states exhibit a series of resonances with characteristic magnetic field d ...

Amer Physical Soc2016