A Single-axis Tunneling Microscope for Undergraduate Labs

I will discuss the conception and development of a low-cost z-axis tunneling microscope (ZTM) for learning about quantum mechanics and electronic structure in undergraduate labs. Inspired by the scanning tunneling microscope, this device cuts costs and complexity for the undergraduate lab setting by limiting tip control to the tip-sample separation. To further reduce cost, an off-the-shelf ceramic capacitor (MLCC) is used as the piezo actuator [1]. Students can observe the exponential dependence of the tunneling current on barrier width (I-z), as well as the local electronic density of states (I-V) for many samples under ambient conditions.
[1] J. Chen and Z. Feng, Electron. Lett. 50, 538 (2014).