Concrete Programming Model for computer with quantum accelerator

Published : 8 February 2020

Quantum computers will provide unprecedent performances thanks to a

very different computing model from the classic computers. The

information medium is no longer a 2 states bit but a qbit carrying

analog information.

Besides, the possibility of entangle a multitude of qbits and

manipulate them in a coherent way will provide unprecedented computing

power.

These quantum computers, with specific applications, will be

accelerators of for conventional computers and can not carry a full

application.

This type of heterogeneous architecture already exists: a GPU or a DSP

are pro- grammed from a conventional processor. But in this case the

calculation models are similar and the data use the same

representation: the two’s complement binary format to integer numbers,

the IEEE 754 format for floating point numbers, UNICODE for

characters, etc.

In a quantum machine (as in the vision of DELFT University [3]), it

will be necessary to mix two types of very different calculation

models (Von Neumann and Quantum models) and data representation spaces

that are also different.

This thesis will explore different calculation models and ways to move

from one model to the other. A programming language and tools for

compilation to implement algorithms and make them operate on different

platforms (hardware or simulated) will be the main outcome of the

thesis.

The candidate will have to learn and synthesize a certain number of

knowledge: current quantum machines (via platforms of simulation

and/or real machines), take into account the characteristics of the

physical qbits performed at LETI, discover the calculation models

adapted to quantum computation (ZX calculus [2]), assimilate the

algorithms / applications [6] known in the quantum field.

The subject is pluridisciplinary complex, but CEA is an ecosystem

where all this knowledge is present both in the design of physical

qbits, in the design of physical qbits, in the electronic, in terms of

computer architecture and languages and UGA will provide knowledge,

both at the algorithmic level and at the model level of programming

level.

Through the synthesis of knowledge, the candidate will propose new way

to program quantum accelerators in connection with current programming

languages [7] based on pre-existing models such as the calculated ZX

[2]. With a classic part for the control and access to data and a

quantum part for the accelerated part of the program.

The classical applications [6] of the domain can be used as benchmarks

and will demonstrate the value of the approach, other algorithms will

be studied to identify possible candidate for quantum acceleration.

[1] H. Bohuslavskyi, A. G. M. Jansen, S. Barraud, V. Barral, M. Cassé, L. Le Guevel,

X. Jehl, L. Hutin, B. Bertrand, G. Billiot, G. Pillonnet, F. Arnaud, P. Galy, S. De

Franceschi, M. Vinet, and M. Sanquer. Cryogenic subthreshold swing saturation

in fd-soi mosfets described with band broadening. IEEE Electron Device Letters,

40(5):784787, May 2019.

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[2] Niel de Beaudrap and Dominic Horsman. The ZX calculus is a language for surface

code lattice surgery. arXiv preprint arXiv:1704.08670, 2017.

[3] X. Fu, L. Riesebos, L. Lao, C. G. Almudever, F. Sebastiano, R. Versluis, E. Charbon,

and K. Bertels. A Heterogeneous Quantum Computer Architecture. In Proceedings

of the ACM International Conference on Computing Frontiers, CF ’16, pages 323

330, New York, NY, USA, 2016. ACM.

[4] Harald Homulle, Stefan Visser, Bishnu Patra, Giorgio Ferrari, Enrico Prati, Car-

men G. Almudéver, Koen Bertels, Fabio Sebastiano, and Edoardo Charbon. Cry-

oCMOS Hardware Technology a Classical Infrastructure for a Scalable Quantum

Computer. In Proceedings of the ACM International Conference on Computing

Frontiers, CF ’16, pages 282287, New York, NY, USA, 2016. ACM.

[5] Louis Hutin, Benoit Bertrand, Yann-Michel Niquet, Jean-Michel Hartmann, Marc

Sanquer, Silvano De Franceschi, Tristan Meunier, and Maud Vinet. SOI MOS

Technology for Spin Qubits. ECS Transactions, 93(1):3536, October 2019.

[6] Ashley Montanaro. Quantum algorithms: an overview. November 2015.

[7] Benoît Valiron, Neil J. Ross, Peter Selinger, D. Scott Alexander, and Jonathan M.

Smith. Programming the quantum future. Communications of the ACM, 58(8):52

61, 2015.

[8] Rodney Van Meter and Clare Horsman. A Blueprint for Building a Quantum Com-

puter. Commun. ACM, 56(10):8493, October 2013.

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