Course on quantum physics with experiments

Tuesday 28 Feb 17


Tobias Gehring
Assistant Professor
DTU Physics
+45 93 51 16 49


Ulrich Busk Hoff
DTU Physics
+45 45 25 32 64
Seven students are the first to have completed a course in experimental quantum technology, where the difficult theory has been transformed into something more tangible.

Quantum physics is a difficult subject. Highly theoretical, many students find it so challenging that they drop out. But with quantum technology finding more and more everyday applications in society, there is a need for people who understand it.

DTU Physics has therefore introduced the course ‘Experimental Techniques in Quantum Technology’.

The 3-week course was held for the first time in January.

‘Lots of cool theory and calculations—but no experiments’. This is the normal recipe for courses in quantum physics, which basically deal with phenomena far removed from our everyday experiences.

Whereas classical physics is deterministic—i.e. if you know everything about a system, you can also predict its future development—quantum physics is probabilistic—i.e. based on probability.

The development trend in computer technology is towards ever smaller circuits, and when you reach the nanometre scale, the system begins to behave unpredictably or quantum mechanically—all by itself.
Obviously, there is no interest in a system that cannot be controlled, which is why researchers all over the world are working intensively to develop computers based on quantum technology. Among other things, a quantum computer could be used to develop new valuable materials—e.g. high-temperature superconductors—while others quantum technologies focus on solving problems associated with data security and developing sensors with unprecedented sensitivity.

Photo: Ulrich Busk Hoff

Time to play
On the new three-week course, the MSc students could choose between three assignments, all of which involved finding a practical solution to a quantum technology problem. There were no correct answers—only a requirement to build a system using basic equipment with a small box generating quantum light—so-called entangled photons. One of the groups performed an experiment with sensors, while two others worked on secure communication between two computers.

Mikkel Larsen and Morten Møller—both of whom come from DTU Fotonik—chose the latter option.

Just like the rest of the course participants, they worked on their experiment every day from eight in the morning to five in the afternoon. Having succeeded in getting the security key to work, they are using the last days to introduce an artificial loss to simulate practical application in the real world.

“It has been a great course, very free and with enough time to play and make mistakes,” they say—quickly busying themselves, as they also want to produce a poster for the exam conference.