Optimization of 2DEG InAs/GaSb Hall Sensors for Single Particle Detection

Magnetic sensors having high spatial and stray field resolutions are key elements in many biomedical applications. One promising magnetic detector is a microsized Hall sensor. We present our first results in realising a measurement system based on a Hall sensor made of an asymmetric 2DEG InAs/GaSb-based heterostructure. The work aims to investigate magnetotransport properties of such Hall sensors and optimize their performance. In particular, we focus on examining noise characteristics of the sensor as it allows us to determine and improve the device sensitivity. We show that in investigated devices a magnetic field sensitivity of better than 0.5 mu T/Hz^1/2 (corresponding to a magnetization detection threshold of 2times10⁵ mu_B/Hz^1/2) should be readily achievable at room temperature and at a frequency of around 3 kHz.