# Aravinthan DevarasuChennai Institute Of Technology | CIT · Centre for Nonlinear Systems

Aravinthan Devarasu

M.Sc., M.Phil., Ph.D., (Physics)

## About

15

Publications

1,575

Reads

**How we measure 'reads'**

A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more

31

Citations

Citations since 2016

Introduction

I am working as a Assistant Professor in Center for Nonlinear Systems, Chennai Institute of Technology, Chennai, Tamilnadu, India.
My Research Interests:
Spintronics, Nonlinear Dynamics

Additional affiliations

August 2015 - September 2017

October 2011 - August 2015

Education

August 2010 - September 2011

July 2008 - April 2010

July 2005 - April 2008

## Publications

Publications (15)

In the presence of complexified parity reflection - time reversal (PT)−symmetric Scarff-II potential, we consider the generalized space–time fractional cubic-quintic nonlinear Schrödinger (FCQNLS) equation. By implementing fractal derivative variable transformation, we derive the fractional optical soliton solutions for the considered model. We con...

The oscillatory interlayer exchange coupling (OXC) between ferromagnetic layers sandwiched by non-magnetic spacer layers plays a significant role in spintronic device function. In this work, the effect of OXC on the current-induced magnetization switching process in four different pentalayer nanopillar alloys is numerically investigated by solving...

The magnetization switching dynamics of the free layer in the pentalayer nanopillar is studied by numerically solving the dynamical equation governed by the Landau–Lifshitz–Gilbert–Slonczewski equation. The magnetization switching time in the absence of orange peel coupling for an applied current density of \(7 \times 10^{11} Am^{-2}\) is 207 ps. T...

In this paper, we investigate the stable propagation of soliton in Complex Ginzburg–Landau (CGL) equation with self focusing nonlinear mode in the presence of PT-symmetric Gaussian potential. In our model, we find the required condition to obtain the stable solution is that the value of spectral filtering is negative and the positive values of diff...

We derive fractional soliton and rogue wave solutions of the space–time fractional nonlinear Schrödinger (FNLS) equation in the existence of complex parity reflection - time reversal (PT)−symmetric and time-dependent potentials. We find that the fractional derivative variable transformation is a good approximation to reduce the space–time FNLS equa...

We explore the existence of stable optical soliton in collisionally inhomogeneous cubic, quintic and septimal nonlinear Schrödinger equation with the presence of a PT-symmetric harmonic-Gaussian potential with unbounded gain-loss distributions. For the various strengths of PT-symmetric potential, we obtain stable optical soliton for a particular ra...

We investigated the influence of oscillatory interlayer exchange coupling (OXC) on spin transfer torque (STT)-assisted magnetization switching in the pentalayer nanopillar structure. The impact of OXC between the ferromagnetic layers in the pentalayer nanopillar is realised by solving the associated governing equation, namely Landau-Lifshitz-Gilber...

The effect of biquadratic coupling on spin transfer torque-assisted magnetization switching in the pentalayer nanopillar device is studied by numerically solving the magnetization switching dynamics of the free layer governed by the Landau- Lifshitz-Gilbert-Slonczewski (LLGS) equation. Magnetization switching time in the absence of biquadratic coup...

Spin transfer torque induced magnetization switching has recently attracted much interest due to its potential applications in magnetic random access memory (MRAM), fast programmable logic, high-density magnetic storage devices, magnetic sensors and in high frequency devices for telecommunications. Magnetic storage devices and magnetic sensors base...

We have studied the effect of orange peel coupling on spin transfer torque magnetization switching in different nanopillar devices. The magnetization switching dynamics of the free layer of the nanopillar device is studied by solving the dynamical equation governed by a Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation. The switching time is calc...

The spin transfer torque assisted magnetization switching in a pentalayer nanopillar
device is theoretically studied for different biasing configurations. The magnetization
switching time is calculated for three different configurations (standard(no biasing),
pinned layer biasing and free layer biasing), by numerically solving the governing
dynamic...

The effect of biquadratic coupling on spin current induced magnetization switching in a Co/Cu/Ni-Fe nanopillar device is investigated by solving the free layer magnetization switching dynamics governed by the Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation. The LLGS equation is numerically solved by using Runge-Kutta fourth order procedure for...

We have studied the effect of biquadratic coupling (BQC) on critical current density in the Co/Cu/Ni-Fe nanopillar
by solving the magnetization switching dynamics of the free layer which is governed by Landau- Lifshitz-Gilbert-Slonczewski (LLGS) equation. The LLGS equation is analytically solved for the time independent case and value of the critic...

The impact of orange peel coupling on spin current induced magnetization switching in a Co/Cu/Ni-Fe nanopillar device is investigated by solving the switching dynamics of magnetization of the free layer governed by the Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation. The value of the critical current required to initiate the magnetization switc...

## Questions

Questions (5)

The magneto-crystalline anisotropy constant of the following ferromagnetic alloys is required.

CoPt

CoFeB

Fe85B13Ni12

EuO

FePt

Fe70Cr30

Can anyone tell the values of the above/ suggest some papers?

Thanks in advance!

Normally in trilayer structure (Pinned / spacer (nonmagnetic metal) / free layer), status of the free layer was read by the analyser kept in the top of free layer. But in the pentalayer (Pinned layer 1 / spacer (nonmagnetic metal) / free layer / spacer(nonmagnetic metal) / Pinned layer 2), the additional pinned layer is kept above the free layer. Theoretically, we can easily study the magnetization switching by solving the dynamical equation. Experimentally, how can read the magnetization status of the free layer in the pentalayer structure?

We have take a trilayer nanopillar consists of two ferromagnetic layer separated by a nonmagnetic metal layer. Suppose if we consider ferromagnetic layers are align parallel(and aligned along easy axis, say X-axis) and ferromagnetic layers lies in XY-plane, then RKKY coupling arises due to the conduction electron reflection at the interface of the ferromagnetic layer. We can be express it interms of the coupling field. My doubt is, In which direction the coupling field will act (in which direction we express the magnetization in the field equation)?

P.S: I herewith attached the article having the expression for RKKY field.

RKKY coupling or oscillating interlayer exchange copuling between the two ferromagnetic layers separated by a nonmagnetic spacer.Conduction

electron reflection at the interface of the ferromagnetic layer produces a RKKY or coupling field. In which direction this field will act?

Equation for the RKKY or Oscillating interlayer exchange coupling field contains the following parameters

- Amplitude of the interlayer coupling(J)
- Thicknesses of the free layer(t
_{f}) and spacer layers (t_{s}) - Period and Phase of the oscillating electron.
- Magnetic material name or vlaue of saturation magnetization.

Can anyone suggest the article / book contains the above parameters?