# WP2 Quantum architecture and software

Computing / Physics / Maths

(Coordinator: M. Mhalla) We will build a common paradigm for physicists and computer scientists. To a large extent, the (layman) experimental physicist still focuses on realizing universal single and two-qubit gates within the standard framework of circuit quantum computation. On the other hand, a computer scientist focuses on algorithms, and their implementation with (i) architectures (hardware) and (ii) languages (software).

**(i) The main objective**is to develop architectures specifically adapted to the different quantum computation models and qubits that we develop in Grenoble (see WP1). This task will benefit from the strong expertise existing at LIG and CEA-LETI in the field of classical computing, and in Néel and CEA-INAC on quantum computing. We shall especially explore how to map a computing model onto a quantum computer, with the constraints given by the quantum hardware. We know how to encode classical data on classical bits and operators, but many steps are missing for a similar connection between classical data and qubits: what are the quantum operators, what is a "q programming Object", what are the interactions between a classical binary computer and a quantum computer [Val,MH]?

**(ii) Quantum phenomena**bring new applications and require new concepts and ideas in many areas of computer science and information technologies such as improving the efficiency of computing [S94,MMST13,MNS16], Networks and Communication [M12,GKH15], Machine learning [T14], Cryptography [BB84,GHS16] , Languages [V13], Stochastic computation [H15], and Error correcting codes [CDZ13]. In Grenoble, several researchers are interested in these challenges but they are mostly unexperienced with Quantum information theory and quantum physics. One of the objectives of the project is to bring together local researchers interested in all aspects of computation models based on quantum phenomena. Considering the importance of algorithms and architectures for quantum technologies, and the lack of strong expertise, we plan to strengthen this research competence in Grenoble with a special full-time chair during the project. The goal will be to organize and to guide the Grenoble computational community towards quantum technologies.

### Means

2 PhD grants+1 full-time Chair of Excellence (with WP1). We shall encourage co-supervision or twinned PhDs (with WP1) (See Section 2 - Management). The Chair will foster collaboration between the two research areas and create a new expertise in Grenoble.##### Milestones

- M2.1 (T0+24) Build a community of quantum computer scientists with active collaborations with the physicists. The activity will include many public workshops and maybe build a network of excellence on this trans-disciplinary subject.
- M2.2 (T0+48) Develop software adapted to the quantum hardware of WP1. We plan to assess our tool chain on a end-to-end use-case.

##### References

**[MNS16]**Frédéric Magniez, Ashwin Nayak, Miklos Santha, Jonah Sherman, Gábor Tardos, David Xiao: « Improved bounds for the randomized decision tree Complexity of recursive majority . » Random Struct. Algorithms 48(3): 612-638 (2016)**[MMST11]**Mehdi Mhalla, Mio Murao, Masato Someya, Peter Turner « Which graph states are useful for quantum information processing ? » TQC 2011**[S94]**Peter Shor « Polynomial-Time Algorithms for Prime Factorization and Discrete Logarithms on a Quantum Computer » Proceedings of the 35th Annual Symposium on Foundations of Computer Science, Santa Fe, NM, Nov. 20--22, 1994.**[CDZ13]**Alain Couvreur, Nicolas Delfosse, Gilles Zémor « A Construction of Quantum LDPC Codes from Cayley Graphs » IEEE Trans. Inform. Theory. 59(9). 6087-6098. 2013**[V13]**A. S. Green, P. L. Lumsdaine, N. J. Ross, P. Selinger. and B. Valiron « Quipper: A Scalable Quantum Programming Language » Proceedings of the 34th annual ACM SIGPLAN conference on Programming Language Design and Implementation (PLDI 2013), ACM SIGPLAN Notices, Volume 48 Issue 6, June 2013**[BB84]**Bennett, C.H. and G. Brassard. Quantum cryptography: « Public key distribution and coin tossing. » In Proceedings of IEEE International Conference on Computers, Systems and Signal Processing, volume 175, page 8. New York, 1984.**[T14]**David Talbot Microsoft Leans on Machine Learning and Quantum Computing in New Research Strategy - MIT Technology Review". MIT Technology Review. Retrieved 26 November 2014.**[GKH15]**Romain Gay, Iordanis Kerenidis, Hoeteck Wee « Communication Complexity of Conditional Disclosure of Secrets and Attribute-Based Encryption » [CRYPTO 15] 35th International Cryptology Conference, 2015**[H15]**J.?Y. Haw, S.?M. Assad, A.?M. Lance, N.?H.?Y. Ng, V. Sharma, P.?K. Lam, and T. Symul. Maximization of Extractable Randomness in a Quantum Random-Number Generator. Phys. Rev. Applied 3, 054004 – Published 11 May 2015**[JMP12]**Jerome Javelle, Mehdi Mhalla,and Simon Perdix « New protocols and lower bounds for quantum secret sharing » TQC 2012**[GHS16]**Tommaso Gagliardoni; Andreas Hülsing; Christian Schaffner « Semantic Security and Indistinguishability in the Quantum World » CRYPTO 2016**[Val]**Benoit Valiron, doi.acm.org/10.1145/2699415**[MH]**Rodney Van Meter, Clare Horsman doi.acm.org/10.1145/2494568

Published on January 23, 2018

## Contact the coordinator

**M. Mhalla**

**Email:**mehdi.mhalla@imag.fr

**Tel:**+33 (0)457 42 14 30