Today, I had the opportunity to attend a talk on Engineered 2D Quantum Materials by Professor Chandni U from the Department of Instrumentation and Applied Physics at IISc Bangalore. I would say it ignited my passion for fundamental research and made me feel fortunate to be in academia. It rekindled my enthusiasm for being a researcher. I felt the same energy and enthusiasm that I used to get while listening to a cosmology documentary on the Discovery Channel.
Chandni Ma’am was my instructor for the solid-state physics course that I took in 2020. Not only did I learn solid-state physics from her, but there are also other lessons I learned which I want to share here in this post.
My first interaction with her was during my PhD interview, where I recall being asked about Bloch’s theorem and related concepts. I was not particularly proficient in the subject and harbored a strong dislike for condensed matter physics in general. Instead, I had a greater inclination towards high-energy physics, particle physics, astronomy, and cosmology. It was only a few months before I began studying condensed matter physics. Let’s save that for another story about why I ultimately decided to pursue it, despite having firmly resolved to avoid the subject after completing my undergraduate course on CMP.
I would certainly say today’s talk was the first in a real long time where I attended the full talk with attention without dozing off. Why? Because the talk was so well organized. Chandni’s choice of the title of the talk was meticulous and carefully chosen. She explained each of the terms in the title “Engineered 2D Quantum Materials”. Starting off with “Quantum Materials”, she highlighted the usage of the term for strongly correlated electronic systems, citing a Nature review paper from 2012. She explained why certain materials are called quantum, while, in principle, all materials can be explained quantum mechanically. (It is when the kinetic energy of the electrons is comparable or less than the Coulombic interaction, the material cannot be described classically. Historically, the free electron theory of material was the very first theory to derive the transport properties in materials wherein the Coulombic interactions are neglected. Later, materials like superconductors require strongly correlated electrons to be explained.) Dimensionality plays another important role in determining the behavior of material. When you slice apples, what you usually get is apples, with a taste similar to that of an apple. But imagine now, you slice apples and the slice of apple tastes like a pineapple – that’s analogous to what happens when we reduce the dimensionality of a material. As one of the dimensions of the material diminishes, we obtain a 2D material, the properties of which are drastically different from its 3D counterpart. Lastly, she described what she meant by engineering in the context of her research. She described the technique of precisely, in a controlled way, stacking the 2D materials in her lab to obtain exotic devices with rich physics and diverse functionality.Top of Form
Having introduced the subject and the experimental techniques they use, she proceeded to introduce one of the interesting fields of research she works on: “Twistronics” (Saisab et. Al, Nature Physics 2022), wherein she explained how just by changing the angle between two layers of graphene, one can obtain strongly correlated electrons. She explained this using band diagrams and the group velocity of electrons, connecting to the introductory concept she previously motivated of electrons having kinetic energy less than the Coulombic energy. The system they refer to is Twisted bi-layer graphene, and the interlayer angle is called the twist angle. By tuning the twist angle, different superlattices and visually appealing patterns (referred to as the Moiré pattern) emerge with interesting physical properties. Certain angles are particularly intriguing, wherein the material can exhibit exotic properties such as superconductivity and orbital ferromagnetism (a phenomenon in which one can differentially populate the energy levels in the graphene-like system to induce ferromagnetism).
What made me admire her was her research vision. She showed us her research proposal that she submitted to join the department as an assistant professor in 2017, presenting this idea. Then she displayed a slide showing a crowded room at the APS March 2018 conference, where the hot topic of discussion was the recent Nature paper published back then, highlighting the magic of magic angles. This shows that she had a vision and clear picture of the context of her research work.
Apart from that, I observed some of her leadership skills and a few key features of their research group, which I would like to incorporate into mine (in case I become a professor).
- Having a research vision: As a leader of a research group, one needs to have a vision.
- Promoting Teamwork: The projects in her lab were related closely enough so that the research is accessible within the group but distinct enough to be different PhD topics. This helps the people to work as a team while still working on their individual projects.
- Intra-group knowledge transfer: During the talk, she gave credit to those who did the work. From this, I could infer that there is a clear flow of knowledge happening within the lab group in terms of experimental protocols and techniques. The senior-most PhD student had optimized a process, and that knowledge remains and gets transferred to the juniors in the group.
- Involvement with the research problem: From the clarity of the talk, the depth of the physics, and the fact that it was accessible to me, one can infer her involvement with the problem of the project. This must stem from a clear paraphrasing of the research problem and having a fitting context for solving it.
- Presentation skills: She started from the very basics and built up the concepts gradually so that it was a smooth transition to her research field. She demonstrated the context of her research, both historical and current trends. There were ample uses of analogies to simplify the concepts she was explaining. Moreover, she highlighted the students and gave due credit to the students who worked on some specific areas.
But that’s not all. What makes Chandni a charismatic leader is her integrity and effective usage of positive reinforcements (a term used in learning theory in psychology, which crudely means providing a positive reward when the subject achieves a milestone), in appropriate contexts. The following event highlights this:
After the talk, there was a felicitation of personnel who had installed DG for the department, marking a drastic improvement in the department’s infrastructure. Earlier, the department was powered by multiple substations, which posed an electrical safety issue and was problematic for maintenance. The issue was addressed well before 2020 and was recently completed, with efforts led by Chandni Ma’am, who also happens to be a member of the department infrastructure committee. Upon resolving the issue, she ensured to organize a felicitation ceremony for the relevant personnel who installed the DG.
Another example from my experience is when I was a TA for the Solid State Physics course in 2022, where she and my supervisor, Dr. Tapajyoti Das Gupta, were the instructors. Saisab and I served as TAs for that semester. After the completion of the course, she had promised us a treat, and the professors took us for a delicious one.
What I learnt from the above two incidents is a crucial quality of a charismatic leader – giving due credit and taking actions to express gratefulness (such as the felicitation and the treat in the above two examples). To conclude, I gained not only knowledge of Solid-state physics from her during the course, but also gleaned important interpersonal skills and leadership qualities that I aspire to incorporate into my own abilities.