Method and system for finite element modeling and simulation of enhanced magnetoresistance in thin film semiconductors with metallic inclusions

1. A method for optimizing the design of a semiconductor thin film device with at least one metallic inclusion therein, the device having a plurality of current ports, and exhibiting extraordinary magnetoresistance comprising:

calculating the extraordinary magnetoresistance using finite element analysis as a function of an applied magnetic field and the geometry of the device;

calculating the field-dependence of a current flow and the potential of the device;

comparing the extraordinary magnetoresistance, the field-dependence of a current flow and the potential of the device to predetermined qualities; and

modifying the material properties and device geometry to obtain a correlation between the calculations and the predetermined qualities, wherein:

boundry conditions are applied directly to specific sections of the geometry of the device while self-consistently determining the values of the potential at other sections of the geometry from a discretized action integral; and

the potential valued at all current ports are equated to each other.

2. A method for optimizing as in claim 1 further comprising:

using a bandwidth reducer and sparse matrix LU solver for reducing the time required for calculating.

3. A method for optimizing the design of a magnetoresistance van der Pauw sensor comprised of a semiconductor substrate, semiconductor material in the form of a closed contour having an area Aa disposed on the substrate, and a conducting material having an area Ab disposed at least partially within said semiconductor material to form a conducting inhomogeneity, whereby the ratio of the area Aa to the area Ab is selected to maximize the magnetoresistance of the sensor at approximately room temperature comprising:

applying a current to a first port and providing for the current to exit via a second port;

measuring the response of the semiconducting contour by the difference in voltage at a third and fourth port with widths Δ 3 and Δ 4 consecutively;

discretizing the action integral that gives rise to the differentiated equation for the electrostatic potential of the contour;

implementing a variational principle;

equating all nodal values for nodes in the third and fourth ports for defining a unique potential at the third and fourth ports over widths Δ 3 and Δ 4 ;

calculating the effective resistance;

calculating the enhanced magnetoresistance;

modifying the geometry and material properties of the sensor to correlate its magnetoresistance properties to predetermined magnetoresistance properties.

4. A method for optimizing as in claim 3 wherein:

the discretizing is preformed using an unstructured triangular mesh generated by an algebraic integer method.

5. A method for optimizing as in claim 4 wherein:

the triangular mesh is selectively increased in density in regions representing large changes in current distribution.

6. A method for optimizing as in claim 3 wherein:

the variational principle is implemented by varying the discretizing action with respect to nodal variables.

7. A system for designing a semiconductor thin film device with at least one metallic inclusion therein exhibiting enhanced magnetoresistance comprising:

software for selectively meshing the geometric structure of the device with mesh density increasing in regions of the geometry representing large changes in current distribution;

software for obtaining a coefficient matrix from the connoctivity of the mesh;

software for calculating a finite element result from the matrix accounting for the material properties and geometric structure of the device; and

a hardware system for implementing the software, wherein:

a bandwidth reducer is used on the matrix and then it is decomposed into the standard LU form for Gaussian elimination.