WP5 Energetics of quantum computing

Physics / Maths / Industry
(Coordinator: R. Whitney) The aim of this WP is to quantitatively investigate the energetic costs related to quantum computation. It will bridge the gap between quantum thermodynamics and industry.
Both fields are well represented in Grenoble. Theorists of Néel, LPMMC, and IF have developed tools to investigate quantitatively the fundamental limits of cooling of small quantum refrigerators [Whi13], as well as the energetic cost of fighting against decoherence [EHC+16], and erasure processes [HJPR16]. Experimentalists of Néel have a wide range of setups to investigate information and energy transfers at the quantum scale [CHN+14]. From the applied perspective, it is becoming a critical question to estimate the cost of cooling processors and to design the best classical environment to maintain the device’s operating temperature.

Theoretically, we will investigate the ultimate energetic costs to quantum processing, related to heat dissipation induced by irreversible computations. We shall especially develop an energetic approach to decoherence, which is the biggest enemy of quantum computation. This will bring quantitative estimations of the power required to cool down any type of quantum processor, as well as the energetic cost of quantum error correction in various architectures. Practical questions for the industrial transfer of quantum devices will be regularly discussed with industrial partners. The discussions will lead to the constitution of a pluridisciplinary think tank and the building of a roadmap for the energetics of quantum processing.

Experimentally, proofs of information to energy conversion, quantum engines and quantum coolers will be implemented in Institut Néel. We expect a measurement of Landauer's erasure work and fluctuation theorems [ERA15] in hybrid opto-mechanical systems. Studies are already underway on information energy transfers and refrigeration [CHN+14] in superconducting circuits.  Soon the thermodynamics of quantum measurement and decoherence will be investigated via the high-efficiency measurement of quantum trajectories in such circuits.

Means

2 PhD grants. We shall encourage co-supervision or twinned PhDs [Physics/Maths] and/or industrial coaching (See Section 2 - Management)

Milestones


  • M5.1 Energetic cost of elementary quantum tasks, optimization (+24)
  • M5.2 Thermodynamics of information processing: From classical to quantum (+48)

References


  • [ERA15] C. Elouard, M. Richard, A. Auffèves, Reversible work extraction from a hybrid opto-mechanical system,  New Journal of Physics 17, 055018 (2015)
  • [Auf15] A. Auffèves, Viewpoint : Nuclear spin points out the arrow of time, Physics 8, 106 (2015)
  • [EHC+16] C. Elouard, D. Herrera-Martí, Maxime Clusel, A. Auffèves, The role of quantum measurement in stochastic thermodynamics, Nature Quantum Information 10.1038/s41534-
  • 017-0008-4 (2017).
  • [HJPR16] Hanson, Joye, Pautrat, Raquépas, Landauer's Principle in Repeated Interaction Systems, Commun. Math. Phys., (2016) in press.
  • [Whi13] R. Whitney, Nonlinear thermoelectricity in point-contacts at pinch-off: a catastrophe aids cooling, Phys. Rev. B 88, 064302 (2013)
  • [CHN+14] H. Courtois, F. Hekking, H. Nguyen, C. Winkelmann, Electronic coolers based on superconducting tunnel junctions: fundamentals and applications, J Low Temp Phys 175, 799 (2014).

Published on January 23, 2018