Method for determining the spatial distribution of electrical current density in a two-dimensional material device

A method comprising:

• applying a voltage between a first electrode and a second electrode, thereby causing a first current to flow from the first electrode through a conductive material to the second electrode and back to the first electrode;
• while the voltage between the first electrode and the second electrode is also applied between a first probe and the second electrode, placing the first probe on first locations along a first interface between the first electrode and the conductive material, thereby causing second currents to flow from the first locations through the conductive material to the second electrode, through the first probe and back to the first locations;
• while the voltage between the first electrode and the second electrode is also applied between a second probe and the first electrode, placing the second probe on second locations along a second interface between the second electrode and the conductive material, thereby causing third currents to flow from the second probe to the first electrode, through the conductive material and back to the second locations;
• and
• determining a current density within the conductive material using the first current, the second currents, and the third currents.