MFM Current Simulation
Computes the magnetic stray field from an infinite current-carrying strip and the resulting force on an MFM tip. Useful for simulating the MFM response to current-carrying traces and interconnects.
Inputs
| Name |
Type |
Required |
Description |
| field |
DATA_FIELD |
Yes |
Topography used for grid dimensions (x/y size and resolution) |
Outputs
| Name |
Type |
Description |
| hx |
DATA_FIELD |
In-plane (x) magnetic field component (A/m) |
| hz |
DATA_FIELD |
Out-of-plane (z) magnetic field component (A/m) |
| force |
DATA_FIELD |
Vertical force on the MFM tip (N) |
Controls
| Name |
Type |
Default |
Description |
| height |
FLOAT |
100e-9 |
Tip-sample separation in metres |
| current |
FLOAT |
1e-3 |
Strip current in amperes |
| width |
FLOAT |
100e-9 |
Width of the current-carrying strip in metres |
| tip_magnetization |
FLOAT |
1e5 |
Effective tip magnetic moment per unit volume in A/m |
Notes
- The current strip is infinite along y and centred at x = 0, so the field varies only in the x direction.
- Uses the Biot-Savart law for an infinite conducting strip of finite width to compute Hx and Hz.
- Hx is the in-plane field component; Hz is the out-of-plane component.
- Force is calculated with the point-dipole approximation: Fz = mu_0 * m_tip * dHz/dz.
- Useful for simulating MFM response to current-carrying traces/interconnects.
- Equivalent to Gwyddion's mfm_current.c.
