My PhD interview at Cambridge

An inside look at applying for a PhD at Cambridge University

Maxwell Centre (where I had my interview)

Background:

I applied for a graduate MRes + PhD program at the NanoDTC at Cambridge University in Nanoscience and Nanotechnology. My application was accepted for the 2nd round of interviews, where I would have my interview on the 31st January 2020.

For context, I was in my last year studying for an MSci in Natural Sciences at UCL and heard about the PhD program through recently finishing a science-based internship in an electron microscopy lab in Cambridge over the summer where I took part in a Nano Ambassador program run by the NanoDTC.

Interviews:

I had stayed overnight with Nordin, a PhD student (and amazing photographer) I knew in Cambridge the day before my interview who was kind enough to host me. I was going over my application with him and some last minute practice the night before going over any potential questions I would be asked.

In the morning, I cycled to my interview, locking up my bike in the bike sheds outside the Maxwell centre. I arrived and registered along with 13 other students. We were all quite clearly nervous and no one really spoke to each other in the waiting areas, at least at the beginning anyway.

We were brought into a meeting room and given a quick talk about the planned schedule for the day and left our bags in an office as we wouldn’t be needing them. Everything was meticulously planned, and we would be continuously supervised from 9am-5pm, by both course administrators and current PhD students who would give us guided tours and chats about their research. We were ushered off sporadically for our interviews, and would have 2 interviews, each for 20 minutes.

Interviews are very sciency, as you’d expect. I don’t go into heavy detail such that the article is accessible to people without a formal science background but left in it for those that are interested. Feel free to skip reading these sections.

1st interview:

I was called into a small room, I sat down and opposite me were my 2 interviewers.

At Cambridge, One-to-one interviews are no longer conducted, so you tend to have 2 people, sometimes 3 people interviewing you at a time as opposed to one person like most other interview scenarios.

Of the two people, one of whom was a co-director of the program, and the other was a reader with her own energy storage/applications lab whose research I was less familiar with. The interview began with them briefly asking me about my master’s research project and previous research project on electron microscopy from my written application. They gave me the option of picking which one I wanted to discuss further which was nice. Given I knew the co-director uses electron microscopy in her own research I suggested we should talk about my project in that area.

We began by mentioning the need for research in this area. We discussed the history and evolution of using electron vs light microscopes and the need for electron microscopes for imaging at high resolution and more recently the need for electron microscopes for imaging biological molecules.

We then discussed difficulties using electrons for imaging different specimens. She wanted me to give a general answer about the difficulties associated with using electrons compared to light/photons for imaging (as they have a charge and hence an electron charge build-up on the sample can deflect the beam). But I didn’t answer this well, and mentioned in regards to imaging something polar and with a partial charge, although I got to the answer in the end with a little help from them.

I could tell my answers weren’t what they were looking for as they both started writing things as I answered the question. It’s not that my answer was wrong per se, just wasn’t specific enough and wasn’t following the correct line of thinking to reach the answer.

We then discussed radiation damage of biological specimens in electron microscopy, and how samples degrade overtime, compared to other more stable materials, e.g. metals. We then spoke about 3d imaging by stitching together different orientations of 2d images (specifically single particle cryoEM).

Fun fact: This work would be responsible for multiple Nobel prizes. Aaron Klug won the nobel prize for chemistry in 1982 for first demonstrating this. He was supervised by Rosalind Franklin before she passed away. She played a key role in the discovery of DNA, but the discovery was ultimately made by Francis Crick and James Watson at the Cavendish laboratory, which I could see from the window of the building where my interview was taking place, which was rather inspiring.

We then spoke a little more about my research, and why open-source research is important in science, and potential future work for the project. Coronavirus was mentioned at one point. Which looking back was eerily foretelling for the next few months which followed.

I began going off on a tangent in relation to one of the questions she asked. At one point, I stopped myself, and pointed out that I hadn’t actually answered her question, and asked her if she could repeat it. I felt rather embarrassed, but they didn’t seem to have a problem with it and asked me to continue on my train of thought, before going back to their initial question.

Towards the end I was asked why I applied to this program specifically given my background and not any others. Although I had already answered this in my submitted application, I gave a more natural answer in the interview. I mentioned advice given to me by different academics/scientists along my journey in science, and felt the NanoDTC was the best natural fit given both its interdisciplinary nature and my own experience and interests. I knew I wanted more experimental/entrepreneurship experience which was offered during the first year masters, and I could continue with the science outreach work done building upon the Nano Ambassador program.

They asked me if I had any questions for them, and I asked about the current/previous students of the course and what they are doing now, which was a terrible question in hindsight. I wish I asked them about the big picture of nanoscience research, and how it’s changed in recent years.

At the end I mentioned how I felt the interview didn’t go well, but they didn’t give anything away. I always enjoyed speaking about science and given how nervous I was at the beginning, I actually enjoyed the experience looking back, despite my initial reaction of thinking the interview went terribly. I thanked them and pushed my chair under the desk and left the room.

I joined the rest of the group, and breathed a sign of relief now that my interview was over. It wasn’t as daunting as I made it out to be in my head leading up to it.

We then had a tour of the chemistry department in Cambridge (which I now work in funnily enough) by a PhD student who was researching hydrogen gas extraction from waste to be used as fuel. None of us were particularly talkative, so I asked her why she applied to the NanoDTC over other programs, borrowing the same question the interviewers asked me which was a little cheeky of me since technically that’s plagiarism and very much frowned upon in the academic community. Unfortunately I can’t remember her answer, but I do remember her saying she loved the NanoDTC, but misses the Californian weather back home.

We eventually made our way back to the nanoscience department where we had a buffet style lunch, with a few PhD students, some on whom I had met previously from my Nano Ambassador program. One of them had pointed out to me “Noticed how you have been supervised all day”. It dawned on me then that it was clear that we didn’t just have 2 interviews, but the whole day was used to assess us, even outside our interviews on our tours, PhD students could be giving feedback of the candidates and get a feel for what they would be like on the course. Like a secret interview, an interview you’re unaware of.

After lunch I had another tour of the Cavendish department. The Cavendish has arguably the richest history of any research laboratory. In other words, I was geeking out rather heavily. After the tour I had my second interview.

2nd interview:

My 2nd interview was a blur, as I sat down I felt my mind go blank, as if I had forgotten everything I knew. I had read up that It’s somewhat common in interviews, and just tried to relax the best I could and not panic about it.

After the introductions they asked me about my research topics, and focussed on my master’s research project on ferroelectric materials. They asked me to explain it, and then what experiment’s I have done to investigate various properties. I spoke about some experiments I had done and what I can deduce from them, namely x-ray diffractions, atomic force microscopy, electrical measurements and thin film deposition.

They asked me to speak more about the electrical measurements I had done, and to draw a circuit for them in the paper in front of me. They then asked me about the electrical circuits and whether current flows through a capacitor in an oscillating circuit. I said I think so. They then asked me not to guess and further questioned why I think it does.

I needed a few prompts as I was stuck. I struggled to reach the answer in the interview, my mind was simply blank. In hindsight it was a very straightforward question and answer. Current is the rate of change of charge with time, since the charge changes on the capacitor plates, that must mean that current flows between them.

They then asked me about hysteresis, and to draw a diagram for hysteresis for both ferromagnets and ferroelectrics.

They asked me how I conducted the experiments, as there is much debate in the field in regards to how these measurements are taken and how the results are interpreted. My favourite paper is on this topic, where a professor was so frustrated with people constantly misinterpreting these experiments, he had one of his students perform the same experiment on a banana to show that it too showed the same phenomena, despite clearly not being a ferroelectric material and hence the interpretation was incorrect. It’s cited over 600 times despite only being 2 pages long. The student who conducted the experiment on the banana would go onto run his own research lab, and eventually be my supervisor for my masters research project. Although thankfully he didn’t get me to do any electrical measurements on bananas that he had to do as a student.

When explaining the hysteresis electrical measurements, I fumbled heavily. I had missed out on a key initial step of the process to ensure a good electrical contact, usually done by sputtering gold onto the sample as gold is a very conductive material. I knew I had missed a step, but wasn’t sure which one. I wasn’t sure about the specific experimental details as I was yet to do them at this stage of my research project, instead focussing on conductivity/bandgap measurements. I told them how I wasn’t sure on the experimental steps as I was yet to do them, and they decided to move onto experiments I had done.

They then decided to ask me about atomic force microscopy. I explained how an AFM machine works, and using it to measure the surface topology. They quickly moved onto a different topic.

They don't care what I knew, they cared more about how I think

This is really important to emphasize. They didn’t seem to care if I knew how an AFM machine worked. They would always skip over and dismiss questions/topics I could answer easily and instead focus on questions and topics I didn’t know or wasn’t aware of. They wanted to see how I would approach a problem I was unfamiliar with, and how I would reason my thoughts and ideas.

They then asked me more about why I’m investigating Hafnium Dioxide compared to other materials. I spoke about how previous perovskite ferroelectrics suffer from size defects and lose their ferroelectric properties, whereas hafnium dioxide doesn’t follow the same issues, and has the added benefit of being compatible with silicon, compared to traditional perovskites, and hence use in microelectronics.

They then asked how I measured the thickness of my samples given how small they are (40 nanometres, which is around 1000 times smaller than the width of human hair). I spoke about my experiments of measuring and fitting laue oscillations to the x-ray diffraction patterns to deduce the thickness.

They then asked me about volatile/non-volatile memory systems, and whether hafnium can be used as a non-volatile memory system. I said yes, but asked them to clarify what a non-volatile memory system is. I knew it was as I attended a talk 2 weeks prior where they mentioned it. I knew the answer, but not the understanding why. They emphasized that I should always ask for clarification if you don’t understand something.

A non-volatile memory system is one that retains its information (i.e. a 0 or a 1 in the case of a bit e.g. transistor) while it’s not powered and retains it’s information. This has many benefits. Namely, you can turn your computer on and off without losing your data, but also you have massive energy savings since it doesn’t need to be constantly powered to retain it’s information.

They finally asked me about my interest in science entrepreneurship. They asked if I was given £1 million to invest into an area nanoscience that would yield the greatest return of investment, what it would be?

I was put on the spot and I mentioned I would invest in drug design, as I had misinterpreted the question as to which area of nanoscience was the most profitable.

They told me that a £1 million investment is nothing to pharmaceutical giants such as astrazenca and GSK, and if maybe I had other ideas. I mentioned investing in new types of ferroelectric memory systems, given they are quite new promising technology and I as familiar with them from my own research, but it was clear my interviewers were quite dismissive of the idea, saying there are better/more promising memory systems than them.

Looking back I wish I mentioned one of the spinout companies my interviewers were part of. Not only would it show I had read up on them, but they would clearly have to agree, and hence make me (and them) look good. It’s a win win! If you wouldn’t invest money into your own company, is it reasonable to ask someone else to? But alas I was put on the spot and my answers were pretty abysmal. Predicting future companies/technologies to invest in turns out to be quite difficult, even for venture capital companies.

It was a bit of a blur, but just like that the interviews were over.

My 1st interview didn’t go great, this one went even worse. I decided to just forget about it, since being annoyed would only be wasted energy, as I can’t change anything now. I joined the rest of the candidates and spoke about their own research projects which was far more welcoming since everyone was less stressed now we had all finished our interviews. Most candidates told me that their interviews went well. I’m not sure if they were lying, telling the truth or I was simply more self-aware.

Socializing with other students:

They had organised a visit to a Mexican restaurant for all the candidates which was awesome of them to do, including a few of the master students on the program. As I knew Cambridge quite well, I told them I’d meet them there, and decided to get some space, it had been a long day. As I left to pick up my bags from downstairs, I saw all the interviewers in a room downstairs chatting. I couldn’t hear what they were saying, but they looked very serious indeed, likely discussing who they would give offers to and who they would reject. I was wondering if they were chatting about me.

I went back to Nordin’s flat as he gave me the key. He came back from his lab, and we chatted about how my experience was. I told him how I felt I hadn’t done well enough and it showed me I didn’t belong there. He was rather shocked saying I’m sure it couldn’t be that bad. I told him how both my interviews went terribly, and he did a great job reassuring me, telling me that even his interviews didn’t go great.

We chatted for around 30 minutes before I headed to the Mexican restaurant to join the rest of the group. I spent most of my time chatting to another candidate who was working in industry for an energy company in Birmingham where he had done his undergrad/masters degree, but that he wanted to return to academia. He also mentioned how his interviews didn’t go too well which we bonded over, so I was somewhat relieved knowing I wasn’t alone.

I chatted to a current masters student on the program about his own experience, and how much he loved his course. He was currently doing a biophysics placement on tissue stiffness so we got chatting about biology/biophysics and how to alter tissue stiffness and how tumours tend be stiffer than their surrounding healthy tissue. I found myself naturally speaking about science even outside the lab or interview setting, and it reinforced the idea that science is for me. Because I really do enjoy it. Just maybe not the interviews.

I finished my dinner early, and had to head off as I was going to a formal at St John’s College with Nordin which he kindly planned for me after I finished the interview. Nordin doesn’t drink, so I ended up drinking his alcohol too. In hindsight alcohol is probably not the best way to deal with the rejection, but one that is all to frequently used. Both for relationships or PhD interviews in my case.

After the formal I headed with Nordin to the Clare College MCR bar for post formal drinks. I visited Clare college when I was 11 as part of an outreach program to encourage applicants from under-represented backgrounds. Now 11 years later I’m getting drunk in their MCR celebrating me finishing my PhD interview. How times have changed. I guess the outreach program worked?

When Midnight struck, it was 1st Feb 2020, and it marked the UK leaving the EU. To celebrate the occasion a few white upperclass students in the bar burst into singing “rule Britannia. It remains as one of the most elitist things I think I have ever witnessed. Cambridge can be quite the bubble for elitism, and has arguably been a breeding ground for the elite for the last 500 years, but that’s slowly changing. Increased diversity along with record levels of state school educated students and new scholarship opportunities means often the impression of Cambridge university is very different to what it actually is.

The MCR bar closed and I went back to Nordin’s to sober up. I travelled back home the next morning.

On the journey home I reflected on my experience and came to the conclusion my performance wasn’t good enough to merit me being accepted. Fortunately for me, Cambridge had other ideas.

Response from Cambridge

On the Monday 3rd of February, I was in UCL’s canteen having lunch after a lecture. I checked my emails on my phone and saw I had an email from Cambridge, which I assumed would be their rejection email. But I was shocked to realise I was given an offer which was fully funded. I had the interview on a Friday, by Monday I heard back that I had been accepted. Within one working day. Although given what research is like in Cambridge, it’s more like 3 working days.

I looked around me, but didn’t have anyone to share it with. I gave myself a little fist bump and messaged Kou to tell him the good news. He was the first person I told and It seems rather fitting that he was also the same person who inspired me to write this article based on him writing about his own interview which you can read here.

I guess the main takeaway I have is that it’s impossible to judge for yourself how well you did in your interview. It’s easy to doubt yourself in situations like these and suffer from imposter syndrome for thinking you’re not good enough and that you don’t belong. My advice would be to trust the process and do the best you can. Besides, you definitely won’t get in if you don’t apply, so why not try?

I’d like to thank Kou for the inspiration of the article, as well as Nordin and Tom for reading the first draft.

If you’d like advice on PhD interviews, please read my following article!