Nathan Langford

Nuts! Fell at the last hurdle... Thanks to everyone who voted for me to get me to the last 2. Had a lot of fun doing this...

Favourite Thing: I love the moment when you come up with a new idea that you think no one’s thought of before and you don’t know if it’s brilliant, a little bit crazy or just plain wrong. That’s when I go to friends and colleagues to get them to try and pick holes in the idea. Talking about new ideas gets me thinking outside my comfort zone and that’s lots of fun.



Kenmore State High School in Queensland, Australia (1991 – 1995); University of Queensland, Australia (1996 – 2007… yikes!!)


B.Sc. (hons.), B.A., Ph.D. (physics)

Work History:

University of Vienna, Austria (2007 – 2009); University of Oxford, UK (2009 – 2011); Royal Holloway University of London (2011 – now)

Current Job:

I’m a postdoctoral researcher studying nanoscale superconducting quantum circuits.


Royal Holloway, University of London

Me and my work

I used to play with lasers, but now I play with superconductors (so cold, they’re even colder than space!) – all in order to try and build a quantum computer, which could simulate DNA, show that photosynthesis is really quantum-powered, and make unbreakable cryptocodes.

My Typical Day

Right at the moment, I’ve just moved fields (from lasers to superconductors), so I’ve kind of gone back to being a student (but with no classes) – my typical day involves a lot of reading (textbooks mostly), doing calculations and learning to build and operate new types of lab equipment (complicated electronics, etc).

What I'd do with the money

In the spirit of the X Factor style of “I’m a Scientist”, I want to let the students decide how I’m going to use the money. Option 1: I would commission a custom glass liquid-helium dewar which would allow students to see inside “live” to watch demonstrations of superconductors and superfluids. Option 2: I would buy a range of equipment and materials, including lasers, optical fibres, a plasma ball and a smoke machine, to allow us to give students demonstrations about lasers – how they work and what they’re used for. You decide!


In my new field where we study and use quantum systems made from engineered nanoscale, superconducting electronic circuits, our electronic circuits only behave “properly” (like purely quantum systems) if we make them really cold… and by cold, I mean *really* cold, ridiculous cold, in fact – up to 1000 times colder than space!!  To do this, we use some of the coldest refrigerators anyone can build – called “dilution refrigerators”.


Dilution refrigerators are highly complex, advanced pieces of equipment, which require very high-quality engineering, but at their heart, it turns out that the fact they work at all is just a bit of a fluke of nature, because of some weird and wonderful properties of liquid helium, which we use as the refrigerant in our dilution fridges.

In some ways, Helium is kind of magic stuff.  It is the second-simplest element and the simplest noble gas, made up of just two electrons, two protons and one or two neutrons.  However, already, with just those 5 or 6 elementary particles, it is too complex to derive its properties from the basic principles of quantum mechanics exactly – without making a bunch of approximations.  And studying its behaviour has given rise to an entire, long-standing field of physics (“Helium physics”) in its own right!  One of the weirdest things about Helium is that it’s what is called a “quantum fluid”.  That means that, no matter how much you cool it down, even if you cool it to absolute zero temperature (no energy at all), it still won’t turn into a solid. Already, that makes it completely different from most of the materials we see in our everyday lives.  Moreover, at low enough temperatures, it also becomes a “superfluid” – a liquid that has no viscosity or drag.  So you couldn’t float or swim in a superfluid Helium sea (quite apart from the obvious freezing to death problem).

But it turns out that the most important thing about Helium as far as our fridges are concerned all comes down to whether the individual atoms have 1 or 2 neutrons (called “Helium 3” or “Helium 4”).  It turns out that 1 little extra neutron is enough to completely change the physical properties of a fluid of Helium and we use those differences to power our dilution refrigerators.

In the Physics Department at Royal Holloway University of London, where I work, we run a lot of “low-temperature” science demonstrations for students and the general public, both on campus for people who visit the university and in visiting schools.  We want to build a special glass bottle (“dewar”) for holding liquid helium to demonstrate some of the strange properties of superfluids, such as spontaneously emptying glasses.  This will also allow us to show people about the behaviour of superconductors (when a metal becomes a superconductor, it can conduct an electrical current with no resistance), which is the key to understanding the stuff we actually research when we put one of our nanofabricated electronic circuits into a dilution fridge.  Normally all of these experiments would need to be done inside a highly insulated liquid-Helium dewar and these are normally not see-through.  I would use the prize money from “I’m a Scientist” to order a custom-designed and built glass dewar so that people can actually watch these experiments happening right in front of them when we’re giving demonstrations to school students.


I my old field of research, we also studied “quantum circuits”, but of a different type – we studied “light” circuits, where we used individual packets of light, called “photons”, as our quantum systems, and we created these photons using lasers.  It turns out that light is a really beautiful quantum system, because you don’t need to make everything cold in order to see it behave quantum mechanically, like you do with a superconducting circuit.  And lasers are a special type of quantum light that makes this all possible.


Lasers are really amazing and that’s not just because they look cool.  When the laser was first invented, it was a curiosity.  Everyone thought it was a nice toy, but had no practical application.  Now, however, lasers are involved somehow in almost every aspect of the technology of our daily lives – and not just fancy things like laser surgery.  You use a laser every time you get something scanned in a shop, play a CD or DVD, or make a long-distance phone call.  Lasers are even used to make jeans and make sure football fields are level!

Because the Physics Department at Royal Holloway has a specialisation in low-temperature physics research, we give lots of demonstrations to school students and the public about low-temperature science.  However, since I’m someone who comes from a background of working with lasers and giving laser science demonstrations, I thought it might be a good idea to buy the equipment required to give laser demonstrations here too, so that students at schools or who visit have the possibility to learn about more different types of science.  I would use the prize money to buy a range of different equipment for showing where light comes from, how lasers work and what makes laser light special.  This equipment would help to demonstrate fluorescence, waves, resonators and lightning, all of which makes up part of how a laser works, and to show some of the applications of lasers, including eye tests and optical fibres!


Which of these options do you like the sound of?  You can vote any time during the “I’m a Scientist” event and I’ll count up the votes to make the decision.

My Interview

How would you describe yourself in 3 words?

No off switch.

Who is your favourite singer or band?

The Cat Empire – one of the best live bands I’ve ever seen.

What is the most fun thing you've done?

Off the top of my head, this probably has to be something from the “travelling the world” category, although choosing one is hard, so: wandering the back streets of Istanbul trying to find where the locals eat; snorkelling on the Great Barrier Reef; or throwing giant snowballs over the edge of Zion Canyon in the US.

If you had 3 wishes for yourself what would they be? - be honest!

This week? Buy a car. Short-term future? Getting my baby-grand piano tuned – it really needs it. Long-term future? Find the time to travel around Australia and see the things that I’ve only heard about.

What did you want to be after you left school?

I didn’t really know yet – there seemed to be too many fun things to do. There were so many different possibilities out there and I felt much too young to be making “important decisions” about what I wanted to be “when I grew up”.

Were you ever in trouble in at school?

No, not really. I was a bit of a nerd who also played sport. The main thing I did that used to get into trouble sometimes was reading under my desk during class and not paying any attention to my teachers.

What's the best thing you've done as a scientist?

I think the best thing I’ve done as a scientist is film and present some segments for an Australian science TV show for kids, called Scope (my first episode is even available online:

Tell us a joke.

How do you tell the difference between an extroverted physicist and an introverted physicist? An extroverted physicist looks at *your* shoes when they talk to you, rather than their own. (I normally tell this joke about mathematicians…)

Other stuff

Work photos:

Lasers make cool toys and better pictures!


These fridges are some of the coldest fridges on Earth… and yes, they are gold-plated!