Comment to the paper “A new Hall-effect enabled voltage amplifier device based on magnetic and thermal properties of materials”

In the paper “Abhimanyu Kumar and Souvik Ganguli ‘A new Hall-effect enabled voltage amplifier device based on magnetic and thermal properties of materials.’ Journal of Magnetism and Magnetic Materials 514 (2020): 167054.“ it is claimed that the output voltage Vout of a Hall plate can be larger than its input voltage Vin. This clearly contradicts the well-known “no-voltage amplification property” of Hall plates. Within this comment we proof the no-voltage amplification theorem by simple methods. Hence, the main statement of Kumar et al. is proven to be incorrect. In addition, we give a simple proof that the solution of the governed equation has a unique solution with regards to the current flow. To illustrate the current flow and the obtained output voltage numerical examples using the finite element method are given.