Interview with the 2025 Nobel Prize laureate in physics John Martinis on 6 December 2025 during Nobel Week in Stockholm, Sweden.

Can you tell us about your childhood?  

John Martinis: Both my parents did not go to college. My father was a fireman, which actually is a very technical occupation where you have to know a lot of safety and you have to understand the physics of fire and the physics of mechanics. I’m sure if he would have had the educational opportunity, he would have gone to college and been a very successful engineer, for example. My mom was a homemaker. She stayed at home and took care of us. We came from a very typical middle class, but not necessarily one with an academic background. But they did really emphasise education and working hard in school. It was a very typical kind of family background where in the end, both my sister and I went to college. It was kind of expected to do that, but not really forced upon that. 

I was very good at math and science. I always enjoyed that. My parents helped me do that. They bought me various science kits when I was growing up, including a mechanical computer when I was 12 or 13 years old, where you put it together. I remember, that was kind of interesting. The other really important thing they did, which I kind of give as a recommendation for parents to think about, which was very useful for me becoming a scientist, is when you come home and you’re sitting around the family dinner table, the parents often ask, “Oh, what did you do today?” and then the children kind of roll their eyes and they don’t say it because it’s such a bland question. What my parents did all the time, was to ask me if I asked any questions during the day, and what were the questions. I think that’s very good training for a scientist, to always be asking questions and to thinking about that and trying to understand and not to be shy. Because it’s kind of hard to ask a question, but if the parents are encouraging you all the time to ask a question, that’s good. When my two boys were growing up, we tried to encourage that. What was good is, being a physics professor, if they asked anything about the natural world, I can go deeper and deeper and deeper, and most of the time get to whatever they wanted to do. If it was in the biology realm, that’s my wife’s background, she could do the same. We kind of had science covered and was able to do that. I’m happy that our children had a good background that way.  

I did well in math and science. I got to take a physics course in high school and really loved it, because it put the math into all the kind of physics I had understood doing things. My dad was always building projects in the garage. I was helping him. I had little projects. I knew how to build things by watching him. He had a kind of an intuitive view of how physics worked, sometimes very simplistic, but he certainly thought into first principles. Getting to a physics class and having someone explain the mathematics to you, was great. I loved physics. Then I went to UC Berkeley which was a great school. At 18, I was being taught by some of the best physicists in the world on how to do physics properly and really enjoyed the challenge at the university. 

What sparked your interest in science? 

John Martinis: A big moment for me was taking the high school physics course. I had kind of intuitively understood a lot of the physics from building things with my father and watching him build things and explaining in a simple way. In the high school physics, I just learned the mathematics behind it in a systematic way. It just made a lot of sense. It was actually kind of easy to study physics for me. I know most people have difficulty studying physics, but for me it was just putting mathematics behind and structure around something I already felt and knew. 

How was your co-laureate, John Clarke, as an advisor? 

John Martinis: I had the good fortune of taking solid state physics from John Clarke from my senior year. I really enjoyed the class. I really enjoyed how he taught it and his very clear, systematic way of doing it. I think I just started asking him questions about what he was doing. And because of what he was doing, I decided when I applied to graduate school, to go to Berkeley and to join John’s group. What I liked about John’s group is that he was measuring quantum noise, noise coming from quantum mechanics, in these electrical devices. What kind of spoke to me is – first of all, my hobby was electronics, I’m pretty good at it – thinking about looking at this macroscopic quantum phenomenon in these devices was really fascinating. Also, as a student, you’re learning quantum mechanics. It’s this amazing subject that’s still a bit mysterious. By doing this, you could then study it and learn it and extend quantum mechanics in a good way. At the time, I had no idea of the experiment I would eventually do for my thesis that would turn into the Nobel Prize, but I just kind of felt that this was interesting and maybe a new direction. It was very intuitive, I didn’t understand the world of physics enough. But John is a good teacher. He was doing interesting research in electronic devices. This all made for a good thesis for me. 

Why is collaboration so important in science? 

John Martinis: Naturally, when I started with John Clarke’s group, I was working by myself, and that was fine, and I enjoyed it, and I was able to make progress. But when we did this experiment for the macroscopic quantum tunnelling for the Nobel Prize, Michel Devoret came in and we started working together with John. You’re naturally collaborating when you’re a graduate student with your graduate advisor. But when Michel came in, I kind of took an immediate liking to him, given that he knew so much more than me –  you know, older, more experience – he understood how physics was done. He especially understood about cryogenic engineering. We had to make a dilution refrigerator. He had the expertise to do that, so I learned a lot from him. I also contributed. I was an expert at electronics, so I could teach Michel at the same time. 

But I would say the most important thing is that Michel and I would be in the second basement working on the experiment, and we would argue about the right way to do it. I think we’re both pretty passionate about doing it the right way, and we would get into these arguments. I think some people would walk by the door and wonder what was going on in there. But by arguing, we kind of figured out what the physics was and what we had to do and what we had to build. I think it was a really important part, that collaboration, in honestly trying to do the best job we could, to figuring out this experiment that enabled us to do this in, I would just say, a beautiful way. I really enjoyed how everything came out with the work. 

Could you share a memory of an exciting moment of discovery? 

John Martinis: I think Michel had gone back to France at the time, and we had gotten the experiment to work, and we were just doing various check experiments on different chips to make sure we did everything right. I put in one chip, which had a higher current – it was designed for higher current – and I was just cooling it down and bringing it up. The first thing we did is, we’d set up the experiment and you put the switching on the oscilloscope. So I was just kind of looking to see if the experiment’s working right, and instead of seeing a band of the switching events kind of as a line on the oscilloscope, I saw three peaks. Those three peaks were the energy level transitions that are kind of the hallmark of seeing quantum mechanics, that I describe in the energy level paper. It’s very clearly showing you the quantum mechanics. Immediately seeing it on the oscilloscope – I can still see it in my mind, those three peaks – I knew we had something special here, and that this would be great. 10 minutes later, I had the computer analyse it and you could see that it was a very beautiful curve. So that to me was the most definitive proof that we were seeing quantum mechanics in the system. I could just see it as a raw signal coming out of the experiment. 

What is a lesson you have learned from failure? 

John Martinis: We first did the experiment, with really high temperatures, and we did it in this simple wiring method, and the experiment was a complete disaster. It didn’t work, didn’t make sense. What happened at that point is we realised we hadn’t really understood it fundamentally. So Michel and I, and John, of course, we sat down and thought about it and understood it was a microwave experiment, and that you had to filter it. We went to the astronomy department and used something called a vector network analyser and read books about how to design the experiment. From that moment on, we built all the elements that we needed, so that the next time we took the data, it looked perfectly right. We then built something that got the really low temperatures and all the data came out. 

Based on a little bit of confusion and taking data, we then figured out what to do. Then it was just a matter of doing the experiment step by step. It basically worked at that point. That was very nice for me as a young student. It is fine to take some data, but you have to sit back and really understand the experiment. There is this Nobel Prize in economics where they talk about the sustained growth and they talk about something called prepositional knowledge. We had to step back and get the prepositional knowledge to really figure out what’s going on. By then, we just had sustained growth, if you like, in the experiment. From that experiment and that prepositional knowledge, it launched the whole field, and other people were able to do good experiments. So that was the kind of the key moment to understand it in that way. In fact, what I always told my students is when we built something that didn’t work, it’s depressing and whatever, but there’s something here that we have to pay attention to, because we learn something. Most of the time that’s right, but some of the time it’s just to make them feel good because their spirit didn’t work and you have to work harder. But all of that was true. 

How do you see the responsibility of a researcher to society? 

John Martinis: The first thing I would say as a researcher is that you have to really look for the truth, and that’s the number one thing you can do. Part of the problem is when you do research, you can take some data, and if your model – your theory – for the data matches the data, it doesn’t mean the theory is true. You can only falsify theories and experiment. You have to be very open to the fact that what you’re thinking about could be wrong or could be confusing. I would say, really looking after the truth very serious. That’s what we did in this experiment. There were already a few experiments out there – it was kind of murky – and we really wanted to prove this phenomenon, macroscopic quantum tunnelling, and numerically with error bars. 

I would say that’s kind of the reason we were successful with the experiment, and that was a good learning experience for me. The thing that worries about me is that there’s eroding of trust of the public into scientific results. I think physics is a little bit better, but in other fields it’s harder and it’s more complicated. I think there’s some studies saying, like half of scientific papers can’t be reproduced or something like that. In my career, we work very hard to make sure the data is right. We do a lot more experiments, that are never published, to check that things are working properly. I was looking at some data this morning of thermal conductivity data, and it didn’t quite look right. So we went back to the people and said “There’s a little mystery here. We have to take the data better, to make sure we’re absolutely clear about that.” That’s an important job of the scientist, to make sure you’re sceptical of your own data. Make sure that when you publish it, you can stand behind it well. 

What advice do you have for young researchers? 

John Martinis: First of all, I think it goes back to what I talked about earlier. You should be asking questions and making sure that you don’t feel intimidated by asking questions all the time. Make sure you’re doing that. Also, as you’re looking at what people are doing around you, make sure you look for, let’s say, little discrepancies in the data or someone’s has a new idea that’s very bold. Make sure you’re looking out for that, because that could be a very important result. It may lead to a Nobel Prize, or at least to an exciting career exploring something. Be open to that. But it takes a while to learn how to do research. I was very fortunate in graduate school, I had John Clarke and Michel teaching me how to do that. Obviously, I learned a lot in my first five, 10 years on my own, how to be a good researcher. But it just takes a while to learn how to do that and to do science at a high level. You just have to be constantly learning. I’m constantly learning. For example, right now, I’m part of a startup company, and I have to learn about business and economics and persuasive discussion of what the plan of our company is.  

I remember in graduate school, I couldn’t make these Josephson junctions. They didn’t work at all. After months of trying different things, I finally went into the clean room and spent the day cleaning out a vacuum system, which was grungy work. But it was only an afternoon, and then everything start working. So, don’t be afraid to roll up your sleeves and clean out your system or do something in order to get it to work. 

I’ve had some downturns in my career and various problems, but in fact all those kind of problems turned into something even better. It’s kind of amazing, various times in my career. Always be on the lookout for what may be a new direction for research, even if what’s happening right now isn’t working out. But yeah, it’s hard to be a researcher and it can be emotionally very difficult for you at times. But in the end, the thrill of doing science, the thrill of discovery, the thrill of writing a paper or giving a talk for the first time, is just so fantastic. All that is quite worth it. 

What environment best encourages creative thinking? 

John Martinis: That’s a good question. In fact, that’s kind of the environment we’re trying to create in my own company. I think what happens is, we have very clear goals of what the company is doing, and they’re a lot more business goal than this typical scientific goal, but it’s similar enough. We make sure that I and the other leaders have good goals and whatever, but we’re giving all the people in us time and effort to be creative. If they have an idea, maybe I’m not a hundred percent thinking that that will work, but as long as it doesn’t take too much time and it can be done in an efficient way, then it’s great. You know, let’s see if it works.  

I would say in my career, a lot of times I’ve been single-mindedly focused basically on building a quantum computer in a certain way. I’ve several times missed out on some good opportunities, but fortunately, other people in the field have done it, and you just take it over. But I want to make sure everyone in our group understands that. We talk a lot about how to be creative. There’s this concept that Alan Ho, my CEO, talks about, that he learned from Amazon, having to do with one-way doors and two-way doors. The basic idea here is, sometimes you make a decision where once you make that decision, you’re just stuck with it and you can’t go back. That happens all the time in experimental physics. You want to buy a really expensive piece of equipment or go in a certain direction and you’re just stuck with that. But a lot of times it’s something called a two-way door where you can go through and try it, but then you can come back and go back to whatever you were doing before. The important thing is to have a discussion with your employees – this is a one-way door or a two-way door – and make sure we all understand the risks and reward and exactly what’s going to happen as you proceed with that idea. 

How do you keep a work-life balance? 

John Martinis: First of all, I’m married to a very wonderful person who will insist on the work-life balance. When I was young, especially in graduate school, I did a lot of rock climbing. I actually donated a climbing guide to Yosemite Tuolumne Meadows as part of that. I found that when I went on the climbing weekend and just focused on doing that, I forgot all about physics because it’s a very intense sport. I came back very refreshed and the like. What I do nowadays – is hard for me to go climbing – I take a lot of long hikes, and I find this to be a creative time for me. I think I’m on the runner’s high where you feel good about everything. But after I go home and I think about it, I reject about half my ideas, because they were not necessarily good ideas. But I enjoy hiking. I enjoy dancing. I take a dance class with my wife. We go to church on Sunday. We try to do things together that doesn’t involve physics. But I like physics a lot, so I spend a lot of time out doing it still. Having other hobbies and focusing on that is quite good. I think I tend to be very intense about doing the physics, so having some other outlets is good. I would say, especially as I get older, I need more downtime or rest time than I used to. 

How might humanity benefit from quantum computers? 

John Martinis: The one thing that I am most interested in, is using quantum computers for solving quantum chemistry and quantum materials problems. This might be by developing a big database of chemical reactions and the like, which you can then use with AI to kind of develop new processes. For example, if you can develop a new process using a quantum computer that is cheaper or uses simpler materials, gets rid of various rare earth materials, more ecologically sound; that can have a huge benefit to humanity that I’m kind of excited about happening. Because around us in nature there is quantum in many of its properties, and if we can harness a quantum computer to solve those problems better, I think we can make a big impact. 

What would you like people to take away from your Nobel Prize discovery? 

John Martinis: I still hear people say that quantum mechanics is the physics of the microscopic, of the small, how atoms work, how molecules work, how fundamental particles work. And that’s true and that’s how it was developed. But we showed that quantum mechanics is actually a much more broader phenomenon than that. You can make electrical circuits and we’ve showed data-based quantum mechanics to it. Other people have looked at mechanical systems or magnetic systems and shown that macroscopic quantum phenomenon is possible. Let’s say the toolbox right now, you think about atoms and molecules, well, it’s expanded into electro circuits and mechanical circuits and other things like that. Because of that, we can build much more expansive or interesting quantum systems than we could have done 40 years ago. A big application of that is of course the quantum computer, but people are also making quantum devices, which have similar principles and are used for doing astronomy applications. For example Ben Mazin, a professor at UC Santa Barbara, is using these kinds of devices to look at exoplanets in astronomy and is using some of their unique capabilities to build these new instruments. In fact, I spent part of my career doing that. I’m really excited to see what’s happened in the last 40 years, developing this technology for scientific instrumentation and hopefully eventually a quantum computer. 

Watch the interview

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