A team of bachelor and master students following courses in quantum optics and quantum information, led by Clément Javerzac-Galy (SB), Marc-André Dupertuis (SB) and Nicolas Macris (IC), has won the second Best Paper Award from IBM Q, given for highest-scientific impact papers by master, PhD student, or postdoctoral researcher.
The objective is to use the first small experimental quantum computers provided by IBM via an online platform (IBM Q Experience), to perform experimental research on quantum algorithms using the IBM Qiskit special software package (open-source). Quantum computing is a totally new paradigm to perform computations by using fragile quantum bits whose states cannot even be copied, but only teleported, through the device. It requires totally new technologies, and the first machines start being available in research labs, and at companies like IBM, Google, Rigetti, Intel. Presently most of these companies try to generate « open source communities » to try and identify new challenges, to foster large scale collaborations and "ecosystems" for new quantum software and new applications.
The adventure started last spring when interested students had to find a research topic. Some students already had the chance to use the IBM quantum computer in their quantum optics and quantum information class, as EPFL was one of the first universities to use it for teaching (voir actualité). Teachers from the sections of Physics and Communication Systems also joined their forces for a collaboration that required a diverse set of skills. It was quickly found that constructing and characterizing different types of complex entangled quantum states could be a good challenge, and each aspect of the enterprise was tackled by small subgroups of students. For instance, Diogo Cruz together with other fellow students, found a way to generate a special class of entangled states more efficiently than previously known. It was also an occasion to test ideas like quantum error correction, which at this stage did not prove efficient. Such entangled quantum states are potentially useful for quantum secret sharing, quantum memories, multiparty quantum network protocols and universal quantum cloning machines.
Participating in the exploration of the new quantum information world is a lot of work, but also fun and exhilarating, even on machines with as little as 16 Qbits. One does not know yet if the quantum revolution in computing will find its « transistor », the invention that allowed since 1947 the large scale miniaturization and diffusion of classical computers in our society, but future engineers and scientists can already be trained on the new experimental quantum machines.
Efficient quantum algorithms for GHZ and W states, and implementation on the IBM quantum computer, D. Cruz, R. Fournier, F. Gremion, A. Jeannerot, K. Komagata, T. Tosic, J. Thiesbrummel, C.L. Chan, N. Macris, M.-A. Dupertuis, C. Javerzac-Galy, https://arxiv.org/abs/1807.05572
Auteur : Marc-André Dupertuis
Source : Institut de physique