Magnetic Cellular Automata wires

Magnetic Cellular Automata wires

Pulecio, J.F. Bhanja, S.
Dept. of Electr. Eng., Univ. of South Florida, Tampa, FL, USA
This paper appears in: Nanotechnology Materials and Devices Conference, 2009. NMDC '09. IEEE
Publication Date: 2-5 June 2009
On page(s): 73 - 75
Location: Traverse City, MI
ISBN: 978-1-4244-4695-7
Digital Object Identifier: 10.1109/NMDC.2009.5167576
Current Version Published: 2009-07-21
Abstract
Magnetic Cellular Automata (MCA) is a novel take on an alternative technological actualization of Boolean logic machines. Not only has it been able to prototypically demonstrate successful operation of logical gates at room temperature; all key components necessary to implement any Boolean function has been realized. We present work further reducing the size of the single domain nano-magnet, approximately 100 times 50 times 30 nm, and physically implement two types of MCA wire architectures ferromagnetic and anti-ferromagnetic. We report the first physical implementation of shape engineered ferromagnetic wires and compare both wires under saturating magnetic fields in the Z direction. We have concluded experimentally, that for conventional data propagation between logical networks, ferromagnetic wires provide extremely stable operation. The high order of coupling we found under saturating magnetic fields demonstrates the flexible clocking nature of ferromagnetic wires and inches the technology closer to implementing complex circuitry.

Invited Paper in IEEE NMDC, 2009

Anita Kumari's work published in IEEE NMDC gets accepted as Invited Paper, 2009

Dr. Bhanja is selected as Program Co-Chair, IEEE ISVLSI, 2009

Dr. Bhanja was selected as Technical Program Co-chair for IEEE ISVLSI, 2009

General Co-chair

Dr. Bhanja was selected as General Co-chair, ACM GLSVLSI 2009

Defect characterization in magnetic field coupled arrays

Defect characterization in magnetic field coupled arrays Kumari, A. Pulecio, J.F. Bhanja, S. Electr. Eng. Dept., Univ. of South Florida, Tampa, FL This paper appears in: Quality of Electronic Design, 2009. ISQED 2009. Quality of Electronic Design Publication Date: 16-18 March 2009 On page(s): 436 - 441 Location: San Jose, CA ISBN: 978-1-4244-2952-3 Digital Object Identifier: 10.1109/ISQED.2009.4810334 Current Version Published: 2009-04-03

Abstract Magnetic Cellular Automata (MCA) utilizes mutual exchange energies of neighboring magnetic cells to order the single-domain magnetic cell which in turn performs computational tasks. In this paper, we study three dominant type of geometric defects (missing, spacing, merging) in array (used as interconnects) based on our fabrication experiments. We study effect of these defects in three segments of the array (near-input, center and near-output) and we have observed that location of these defects play an important role in masking of the errors. The observed simulation results indicate that most of the defects occurring around center and near-output would be masked generating correct behavior while defects in the near-input segment would mostly cause erroneous output. We also observe that MCA is extremely robust towards space irregularities, one of the most common form of defect we observed through our fabrication techniques.

An Error Model to Study the Behavior of Transient Errors in Sequential Circuits

An Error Model to Study the Behavior of Transient Errors in Sequential Circuits Lingasubramanian, K. Bhanja, S. Nano Comput. Res. Group (NCRG), Univ. of South Florida, Tampa, FL This paper appears in: VLSI Design, 2009 22nd International Conference on Publication Date: 5-9 Jan. 2009 On page(s): 485 - 490 Location: New Delhi ISSN: 1063-9667 ISBN: 978-0-7695-3506-7 Digital Object Identifier: 10.1109/VLSI.Design.2009.73 Current Version Published: 2009-01-19

Abstract In sequential logic circuits the transient errors that occur in a particular time frame will propagate to consecutive time frames thereby making the device more vulnerable. In this work we propose a probabilistic error model for sequential logic that can measure the expected output error probability, given a probabilistic input space, that account for both spatial dependencies and temporal correlations across the logic, using a time evolving causal network. We demonstrate our error model using MCNC and ISCAS benchmark circuits and validate it with HSpice simulations. Our observations show that, significantly low individual gate error probabilities produce at least 5 fold higher output error probabilities. The average error percentage of our results with reference to HSpice simulation results is only 4.43%. Our observations show that the order of temporal dependency of error varies for different sequential circuits.

Direct Quadratic Minimization Using Magnetic Field-Based Computing

Direct Quadratic Minimization Using Magnetic Field-Based Computing Sarkar, S. Bhanja, S. Dept. of Comput. Sci. & Eng., South Univ., Tampa, FL This paper appears in: Design and Test of Nano Devices, Circuits and Systems, 2008 IEEE International Workshop on Publication Date: 29-30 Sept. 2008 On page(s): 31 - 34 Location: Cambridge, MA ISBN: 978-0-7695-3379-7 Digital Object Identifier: 10.1109/NDCS.2008.13 Current Version Published: 2008-10-03

Abstract We explore an unconventional front in computing,which we call magnetic field-based computing (MFC), that harnesses the energy minimization aspects of a collection of nanomagnets to solve directly quadratic energy minimization problems, such as those arising in computationaolly intensive computer vision tasks. The Hamiltonian of a collection of bipolar nanomagnets is governed by the pairwise dipolar interactions.The ground state of a nanomagnet collection minimizes this Hamiltonian. We have devised a computational method, based on multi-dimensional scaling, to decide upon the spatial arrangement of nanomagnets that matches a particular quadratic minimization problem. Each variable is represented by a nanomagnet and the distances between them are such that the dipolar interactions match the corresponding pairwise energy term in the original optimization problem. We select the nanomagnets that participate in a specific computation from a field of regularly placed nanomagnets. The nanomagnets that do not participate are deselected using transverse magnetic fields. We demonstrate these ideas by solving Landau-Lifshitz equations as implemented in the NISTpsilas micro-magnetic OOMMF software.

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