Magnonics, an emerging research field that uses the quanta of spin waves as data carriers, has a ... more Magnonics, an emerging research field that uses the quanta of spin waves as data carriers, has a potential to dominate the post-CMOS era owing to its intrinsic property of ultra-low power operation. Spin waves can be manipulated by a wide range of parameters; thus, they are suitable for sensing applications in a wide range of physical fields. In this study, we designed a highly sensitive, simple structure, and ultra-low power magnetic sensor using a simple CoFeB/Y 3 Fe 5 O 12 bilayer structure. We demonstrated that the CoFeB/Y 3 Fe 5 O 12 bilayer structure can create a sharp rejection band in its spin-wave transmission spectra. The lowest point of this strong rejection band allows the detection of a small frequency shift owing to the external magnetic field variation. Experimental observations revealed that such a bilayer magnetic sensor exhibits 20 MHz frequency shifts upon the application of an external magnetic field of 0.5 mT. Considering the lowest full width half maximum, which is about 2 MHz, a sensitivity of 10-2 mT order can be experimentally achieved. Furthermore, the higher sensitivity in the order of 10-6 T (µT) has been demonstrated using the sharp edge of the rejection band of the CoFeB/Y 3 Fe 5 O 12 bilayer device. A Y-shaped spin waves interference device with two input arms consisting of CoFeB/Y 3 Fe 5 O 12 and Y 3 Fe 5 O 12 has been theoretically investigated. We proposed that such a structure can demonstrate a magnetic sensitivity in the range of 10 −9 T (nT) at room temperature. The sensitivity of the sensor can be further enhanced by tuning the width of the CoFeB metal stripe.
Spin waves (SWs), an ultra-low power magnetic excitation in ferro or antiferromagnetic media, hav... more Spin waves (SWs), an ultra-low power magnetic excitation in ferro or antiferromagnetic media, have tremendous potential as transport less data carriers for post-CMOS technology using their wave interference properties. The concept of magnon interference originates from optical interference, resulting in a historical taboo of maintaining an identical wavevector for magnon interference-based devices. This makes the attainment of on-chip design reconfigurability challenging owing to the difficulty in phase tuning via external fields. Breaking the taboo, this study explores a novel technique to systematically control magnon interference using asymmetric wavevectors from two different SW modes (magnetostatic surface SWs and backward volume magnetostatic SWs) in a microstructured yttrium iron garnet crossbar. Using this system, we demonstrate phase reconfigurability in the interference pattern by modulating the thermal landscape, modifying the dispersion of the interfering SW modes. Thus,...
Magnonics, an emerging research field that uses the quanta of spin waves as data carriers, has a ... more Magnonics, an emerging research field that uses the quanta of spin waves as data carriers, has a potential to dominate the post-CMOS era owing to its intrinsic property of ultra-low power operation. Spin waves can be manipulated by a wide range of parameters; thus, they are suitable for sensing applications in a wide range of physical fields. In this study, we designed a highly sensitive, simple structure, and ultra-low power magnetic sensor using a simple CoFeB/Y3Fe5O12 bilayer structure. We demonstrated that the CoFeB/Y3Fe5O12 bilayer structure can create a sharp rejection band in its spin-wave transmission spectra. The lowest point of this strong rejection band allows the detection of a small frequency shift owing to the external magnetic field variation. Experimental observations revealed that such a bilayer magnetic sensor exhibits 20 MHz frequency shifts upon the application of an external magnetic field of 0.5 mT. Considering the lowest full width half maximum, which is about...
Electrically tunable magnon FET controlled by ionic polymer gate
The Japan Society of Applied Physics, Jul 6, 2021
Multifrequency Spin Wave Device for Parallel Data Processing using Micro Structured Yttrium Iron Garnet Thin Films
The Japan Society of Applied Physics, Jan 26, 2021
Spin wave propagation characteristics of defect spinel epitaxial γ-Fe 2- x Al x O 3 thin films for magnonics applications
The Japan Society of Applied Physics, Jul 6, 2021
Colored Noise Induced Synchronization of Ultra-low Power Consumption Spintronics Stochastic Neurons
The Japan Society of Applied Physics, Jul 6, 2021
Low temperature slow dynamics and spin wave life time in Co- and Si-substituted Lu 3 Fe 5 O 12 spin cluster glass thin films
The Japan Society of Applied Physics, 2019
Control of Magnetic properties of spinel ferrite thin film for magnonic applications
The Japan Society of Applied Physics, Jan 26, 2021
EE-15 - Multifrequency Spin Wave Device for Parallel Data Processing using Micro Structured Yttrium Iron Garnet Thin Films
Abstract: Spin waves (SWs) and their quanta magnons in the magnetic structures offer data transmi... more Abstract: Spin waves (SWs) and their quanta magnons in the magnetic structures offer data transmission and data encoding capability in both amplitude and phase, providing an additional degree of freedom compared to their electronic counterparts. Most of the works in this field are focused on developing novel and energy efficient control mechanisms of SW by different means such as voltage [1], current [2], light [3], heat [4] etc., to use it in logic applications. However, this wave-based computation has the tremendous potential of parallel data processing. A multifrequency magnon network would allow parallel data processing within a single element, which is not possible in conventional transistor-based electronic logic. There are few reports about SW channeling in multiple paths in metallic ferromagnet [5][6]. In this work, we experimentally demonstrated a novel multifrequency SW device that can operate at multiple frequencies simultaneously using the shape anisotropy of the magnoni...
A three-bit threshold inverter quantization based CMOS flash ADC
2017 4th International Conference on Advances in Electrical Engineering (ICAEE), 2017
This paper presents a simple and upfront design of a three-bit threshold inverter quantization (T... more This paper presents a simple and upfront design of a three-bit threshold inverter quantization (TIQ) based flash analog to digital converter (ADC) chip. This TIQ based ADC does not require any on-chip or off-chip reference voltage as needed in other ADCs. Switching voltage of an inverter can be set to a required input voltage by optimizing the width-ratio of the nMOS and pMOS transistors in CMOS technology. The chip was implemented and simulated in Cadence Virtuoso and the layout design of the ADC chip was accomplished in Cadence Layout Suite in AMI's C5 process.
We present a comparison of the spin wave propagation in Au/Y 3 Fe5O 12 and Pt/Y 3 Fe5O 12 bilayer... more We present a comparison of the spin wave propagation in Au/Y 3 Fe5O 12 and Pt/Y 3 Fe5O 12 bilayers. Microwave technique with a coplanner waveguide arrangement was used to excite and detect the spin wave. We observed a suppression in the propagating spin wave intensity when a metal stripe is placed on the surface of Y 3 Fe5O 12 in the spin wave propagation path due to the spin pumping from Y 3 Fe5O 12 to nonmagnetic metal stripe. However, a significant difference in the suppression property was observed with the Au and Pt electrode layers, which cannot be explained by the enhancement of the damping constant induced by spin pumping alone. The significant suppression of the spin wave propagation in the Au/Y 3 Fe5O 12 bilayer system is attributed to the spin backflow and two magnon scattering.
2017 4th International Conference on Advances in Electrical Engineering (ICAEE), 2017
The threshold voltage model of ultra thin body (UTB) XOI FET is studied here. 2-D Poisson equatio... more The threshold voltage model of ultra thin body (UTB) XOI FET is studied here. 2-D Poisson equation is solved to calculate the threshold voltage. To incorporate the short channel effects, quantum mechanical correction factors are introduced in the model. Then, the effect of different device parameters on the threshold voltage is investigated.
Spin wave modulation by inserting periodic metal stripe on the YIG surface
The Japan Society of Applied Physics, 2019
Modeling and Simulation of CNT based tunnel FET
Self-organized nanostructures in magnetic CoGa0.8Mn1.2O4 thin films fabricated by pulsed laser deposition
The fabrication of highly-ordered nanostructures by self-organization is one of the greatest chal... more The fabrication of highly-ordered nanostructures by self-organization is one of the greatest challenges in nano science. Herein, we report the formation of a self-organized nanostructure in the CoGa0.8Mn1.2O4 thin film through a thermal annealing treatment. The thin film as-deposited by pulsed laser deposition exhibits a single crystalline phase epitaxially oriented along the [0 0 1] direction the SrTiO3 [0 0 1] substrate. Post-annealing in air was found to promote crystalline phase separation into tetragonal and cubic phases driven by the Jahn–Teller effect resulting in the formation of the nano-zigzag pattern. The structural and magnetic properties of the nanostructured films strongly depend on the annealing time, which can be attributed to the inter-diffusion of Ga and Mn ions.
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Papers by shamim sarker