A paper published in ACS Nano where I was listed as a co-author. This paper investigates controlled molecular diffusion on a graphene field-effect transistor via switching on and off the gate. I worked on this project under the Crommie Group in UC Berkeley under mentorship from Hsin-Zon Tsai.

My involvements in this project were in fabricating the Graphene Field-Effect Transistors (GFETs) used for measurement and assisting with assessing quality of the devices through scanning tunneling microscopy (STM), atomic force microscopy (AFM), and scanning electron microscopy (SEM) with supervision of a graduate student.

A project done in collaboration with lab partner Jake Lansberg.

In this experiment, an aluminum-doped germanium sample was examined via the Van Der Pauw technique to measure the Hall effect in the sample. By recording the voltage drop along different biases across the crystal at a given current and B-field strength, we were able to conclude a functional form of the hall coefficient as a function of temperature. We were also able to determine the type of dopant used (p-type or n-type), as well as the electron and hole concentrations and mobilities. From this, a band gap energy of ∼1.1 eV was determined, as well as the functional dependence of the electron and hole concentrations and mobilities on the temperature.

A full written report of the experiment can be found via the google drive link below the figure.

A project done in collaboration with lab partner Jake Lansberg.

In this experiment, we observe the Hall Effect in a plasma (Helium/Argon gas mixture). We measure data to determine parameters related to discharge currents and voltages, the Hall Field and their relationships to different magnetic fields and pressures, and other quantities related to the electron gas.

A presentation of the project can be found via the google drive link below the figure.

A project done in collaboration with lab partner Jake Lansberg.

In this experiment, we investigate the optical pumping of rubidium isotopes and the resulting Zeeman splitting of their hyperfine energy levels under an applied magnetic field. We used a rubidium discharge lamp to optically pump a vapor of 85Rb and 87Rb into dark states defined by their magnetic sub-levels. These states are probed using optically detected magnetic resonance (ODMR), where an RF magnetic field drives transitions between Zeeman-split levels, producing measurable changes in the intensity of the transmitted light intensity. By sweeping the RF frequency and current in the Helmholtz coils, we demonstrated the linear dependence of Zeeman splitting on magnetic field strength. From our analysis, we can further determine the nuclear spin values for each isotope, and even estimate the ambient magnetic field of the Earth in the lab. Our results are consistent with the theoretical values for rubidium, demonstrating the effectiveness of optical pumping and ODMR as tools for probing atomic structure and experimentally verifying quantum mechanics.

A full written report of the experiment can be found via the google drive link below the figure.

A project done in collaboration with lab partner Jake Lansberg.

In this experiment, we constructed and operated carbon dioxide (CO2) laser to explore the principles of gas lasers, optical alignment, and molecular spectroscopy. Alignment was performed using a visible Helium Neon (HeNe) laser, and lasing was achieved by optimizing mirror positions and maintaining stable gas flow, water cooling, and high-voltage current. We measured current-voltage characteristics at various gas pressures, identified the lasing power threshold, and examined output power stability near threshold conditions. Although difficulties with spectrometer alignment prevented a full analysis of the laser spectrum, we were still able to get partial results and examine further the sensitivity of the laser to optical alignment. Overall, the experiment provided hands-on experience with laser operation and highlighted the practical challenges involved in generating and analyzing infrared laser emissions, as well as revealing the general principles behind how lasers work.

A full written report of the experiment can be found via the google drive link below the figure.

A project done in collaboration with lab partner Jake Lansberg.

A circuit was designed to take in a signal from a microphone and send it to code on a computer such that the frequency of the signal could be determined. From this, we could construct a barebones guitar tuner, where the note could be displayed on a computer screen and a light can be lit depending on whether the note was the desired frequency.

The circuit design is shown in the picture. The project was only in the form of a physical presentation.

A project done in collaboration with partner Brandon Kang.

The discovery of the Higgs boson in July 2012 was arguably the most important event in particle physics. Discovering the Higgs proved that our understanding of the universe, specifically the Standard Model of particle physics, was surprisingly accurate and ultimately was the last piece of the puzzle needed to complete the underlying theory of the fundamental building blocks that make up everything we see around us. Rediscovery of the Higgs gives a chance to gain firsthand experience and greater insight into the data analysis behind such a discovery and, in theory, would allow us to test other regions of the dataset to see if there are any other particles waiting to be discovered.

A full written report of the experiment can be found via the google drive link below the figure.