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Patent number: 10536281Abstract: A magnetic random access memory (MRAM) physically unclonable function (PUF) device that uses the geometric variations in magnetic memory cells to generate a random PUF response is described herein. Within the MRAM, one or more magnetic memory cells can be used for the PUF. The PUF response is generated by destabilizing the one or more magnetic memory cells and then allowing them to relax. The MRAM PUF has also a relatively small footprint among all other silicon PUFs. Timing and control signals for the MRAM PUF are also described along with power and delay characteristics for use with field and spin transfer torque driven destabilization operations.Type: GrantFiled: May 28, 2015Date of Patent: January 14, 2020Assignee: University of South FloridaInventors: Jayita Das, Kevin P. Scott, Drew H. Burgett, Srinath Rajaram, Sanjukta Bhanja
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Patent number: 10517533Abstract: Provided is a Coupled Domain Sensor (CDS) that can be used to, for example, evaluate hydration and occlusion of blood in patients with edema using electrical and optical measurements. Advantageously, the CDS provides a quicker, more effective and accurate way of monitoring this medical condition.Type: GrantFiled: May 16, 2016Date of Patent: December 31, 2019Assignees: The Florida International University Board of Trustees, University of South FloridaInventors: Shekhar Bhansali, Karina Rincon, Jessica Ramella-Roman, Sanjukta Bhanja
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Patent number: 10198402Abstract: A magnetic system for solving one or more quadratic optimization problems by associating each of a plurality of variables of a quadratic optimization problem with a nanomagnet subset of a nanomagnet array, driving the nanomagnets of the nanomagnet subset to an excited state, allowing the nanomagnets of the nanomagnet subset to enter a relaxed state after being driven to an excited state, wherein the nanomagnets magnetically couple with one another in the relaxed state to minimize the total magnetic coupling energy of the nanomagnet array, and sensing a magnetic coupling of the nanomagnets of the nanomagnet subset to solve the quadratic optimization problem.Type: GrantFiled: July 31, 2017Date of Patent: February 5, 2019Assignee: University of South FloridaInventors: Sanjukta Bhanja, Sudeep Sarkar, Ravi Panchumarthy, Dinuka K. Karunaratne
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Patent number: 9720599Abstract: A magnetic system for solving a quadratic optimization problem by associating each of a plurality of variables of a quadratic optimization problem with a nanomagnet of a nanomagnet array, driving the nanomagnets of the nanomagnet array to an excited state, allowing the nanomagnets of the nanomagnet array to enter a relaxed state after being driven to an excited state, wherein the nanomagnets magnetically couple with one another in the relaxed state to minimize the total magnetic coupling energy of the nanomagnet array, and sensing a magnetic coupling of the nanomagnets of the nanomagnet array to solve the quadratic optimization problem.Type: GrantFiled: June 24, 2016Date of Patent: August 1, 2017Assignee: University of South FloridaInventors: Sanjukta Bhanja, Sudeep Sarkar, Ravi Panchumarthy, Dinuka K. Karunaratne
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Publication number: 20170214532Abstract: A magnetic random access memory (MRAM) physically unclonable function (PUF) device that uses the geometric variations in magnetic memory cells to generate a random PUF response is described herein. Within the MRAM, one or more magnetic memory cells can be used for the PUF. The PUF response is generated by destabilizing the one or more magnetic memory cells and then allowing them to relax. The MRAM PUF has also a relatively small foot-print among all other silicon PUFs. Timing and control signals for the MRAM PUF are also described along with power and delay characteristics for use with with field and spin transfer torque driven destabilization operations.Type: ApplicationFiled: May 28, 2015Publication date: July 27, 2017Applicant: University of South FloridaInventors: JAYITA DAS, KEVIN P. SCOTT, DREW H. BURGETT, SRINATH RAJARAM, SANJUKTA BHANJA
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Publication number: 20170060417Abstract: A magnetic system for solving a quadratic optimization problem by associating each of a plurality of variables of a quadratic optimization problem with a nanomagnet of a nanomagnet array, driving the nanomagnets of the nanomagnet array to an excited state, allowing the nanomagnets of the nanomagnet array to enter a relaxed state after being driven to an excited state, wherein the nanomagnets magnetically couple with one another in the relaxed state to minimize the total magnetic coupling energy of the nanomagnet array, and sensing a magnetic coupling of the nanomagnets of the nanomagnet array to solve the quadratic optimization problem.Type: ApplicationFiled: June 24, 2016Publication date: March 2, 2017Applicant: University of South FloridaInventors: Sanjukta Bhanja, Sudeep Sarkar, Ravi Panchumarthy, Dinuka K. Karunaratne
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Publication number: 20160331314Abstract: The subject invention provides a Coupled Domain Sensor (CDS) that can be used to, for example, evaluate hydration and occlusion of blood in patients with edema using electrical and optical measurements. Advantageously, the CDS provides a quicker, more effective and accurate way of monitoring this medical condition.Type: ApplicationFiled: May 16, 2016Publication date: November 17, 2016Applicants: The Florida International University Board of Trustees, University of South FloridaInventors: Shekhar BHANSALI, Karina RINCON, Jessica RAMELLA-ROMAN, Sanjukta BHANJA
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Patent number: 9286687Abstract: A system and method for image-processing that will facilitate automatically analyzing and estimating atomic force microscopy (AFM) images and magnetic force microscopy (MFM) images of fabricated nanomagnetic arrays to identify the magnetization states of the nanomagnets in the array. The system and method will automatically estimate the magnetization states of nanomagnetics disks into one of a plurality of energy minimum magnetization state configurations and provide an annotated image of the results of the estimation.Type: GrantFiled: August 25, 2014Date of Patent: March 15, 2016Assignee: University of South FloridaInventors: Ravi Panchumarthy, Dinuka K. Karunaratne, Sudeep Sarkar, Sanjukta Bhanja
Tuesday, July 28, 2020
MatlabHTM: A sequence memory model of neocortical layers for anomaly detection
Bautista, I., Sarkar, S., & Bhanja, S. (2020). MatlabHTM: A sequence
memory model of neocortical layers for anomaly detection. SoftwareX, 11, 100491.
Spin–Orbit Torque and Dipole Coupling for Nanomagnetic Array Programmability
Nance, J. A., Roxy, K. A., Bhanja, S., & Carman, G. P. (2020).
Spin-Orbit Torque and Dipole Coupling for Nanomagnetic Array
Programmability. IEEE Transactions on Magnetics.
Abstract:
Computational architectures
that rely on an array of dipole-coupled nanomagnetic elements require an
energy-efficient method of programming individual elements within the
array. As a low-energy, selective method of controlling magnetization,
spin–orbit torque (SOT) represents a promising solution. Here, a
finite-difference micromagnetic model is used to characterize the dipole
coupling between adjacent CoFeB nanodisks and to determine the critical
SOT current required to switch these disks. Additionally, a phase plot
showing disk dimensions at which both vortex and single-domain in-plane
magnetic states are stable is produced. A dipole-coupled array’s
response to dynamic application of SOT current is also simulated. The
results show that the rate of applying SOT current to one element in the
array strongly influences the stable states of adjacent elements and
that the SOT current amplitude required for this influence is an order
of magnitude lower than the previously determined critical switching
current. This indicates that SOT current dynamics play a significant
role in the behavior of a dipole-coupled array. Finally, an architecture
to achieve programmability in nanomagnetic computational platforms with
SOT is presented.
Wednesday, July 15, 2020
Spin–Orbit Torque and Dipole Coupling for Nanomagnetic Array Programmability
Keywords:
Abstract:
Computational
architectures that rely on an array of dipole-coupled nanomagnetic
elements require an energy-efficient method of programming individual
elements within the array. As a low-energy, selective method of
controlling magnetization, spin-orbit torque (SOT) represents a
promising solution. Here, a finite-difference micromagnetic model is
used to characterize the dipole coupling between adjacent CoFeB
nanodisks and to determine the critical SOT current required to switch
these disks. Additionally, a phase plot showing disk dimensions at which
both vortex and single-domain in-plane magnetic states are stable is
produced. A dipole-coupled array's response to dynamic application of
SOT current is also simulated. The results show that the rate of
applying SOT current to one element in the array strongly influences the
stable states of adjacent elements and that the SOT current amplitude
required for this influence is an order of magnitude lower than the
previously determined critical switching current. This indicates that
SOT current dynamics play a significant role in the behavior of a
dipole-coupled array. Finally, an architecture to achieve
programmability in nanomagnetic computational platforms with SOT is
presented.
@ARTICLE{9095323,
author={Nance, John A. and Roxy, Kawsher A. and Bhanja, Sanjukta and Carman, Greg P.},
journal={IEEE Transactions on Magnetics},
title={Spin–Orbit Torque and Dipole Coupling for Nanomagnetic Array Programmability},
year={2020},
volume={56},
number={7},
pages={1-8},
doi={10.1109/TMAG.2020.2995514}}
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