Recent Progress on Reversible Quantum-Flux-Parametron for Superconductor Reversible Computing

Takeuchi, Naoki; Yamanashi, Yuki; Yoshikawa, Nobuyuki

doi:10.1587/transele.e101.c.352

“…. This is of the exact same form as the transformation (72). As such, the same conclusion applies: in this case, this transformation corresponds to the CTO described in (15).…”

Section: Transformations On Computational States and Catalytic Thermal Operationssupporting

confidence: 52%

“…The Reversible Quantum Flux Parametron (RQFP) logic family [71][72][73] is a logically reversible variant of the well-developed superconducting logic family AQFP (Adiabatic Quantum Flux Parametron), which has been being developed primarily at Yokohama National University in Japan. RQFP (and its not-necessarily-reversible generalization AQFP) rely on adiabatic transformation of the abstract potential energy surface (PES) that obtains within Josephson-junction-based superconducting circuits.…”

Section: Reversible Quantum Flux Parametronmentioning

confidence: 99%

Quantum Foundations of Classical Reversible Computing

Frank¹,

Shukla²

2021

Preprint

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The reversible computation paradigm aims to provide a new foundation for general classical digital computing that is capable of circumventing the thermodynamic limits to the energy efficiency of the conventional, non-reversible paradigm. However, to date, the essential rationale for and analysis of classical reversible computing (RC) has not yet been expressed in terms that leverage the modern formal methods of non-equilibrium quantum thermodynamics (NEQT). In this paper, we begin developing an NEQT-based foundation for the physics of reversible computing. We use the framework of Gorini-Kossakowski-Sudarshan-Lindblad dynamics (a.k.a. Lindbladians) with multiple asymptotic states, incorporating recent results from resource theory, full counting statistics, and stochastic thermodynamics. Important conclusions include that, as expected: (1) Landauer's Principle indeed sets a strict lower bound on entropy generation in traditional non-reversible architectures for deterministic computing machines when we account for the loss of correlations; and (2) implementations of the alternative reversible computation paradigm can potentially avoid such losses, and thereby circumvent the Landauer limit, potentially allowing the efficiency of future digital computing technologies to continue improving indefinitely. We also outline a research plan for identifying the fundamental minimum energy dissipation of reversible computing machines as a function of speed.

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“…. This is of the exact 1546 same form as the transformation (72). As such, the same conclusion applies: in this 1547 case, this transformation corresponds to the CTO described in (15).…”

mentioning

confidence: 55%

Quantum Foundations of Classical Reversible Computing

Frank¹,

Shukla²

2021

Preprint

View full text Add to dashboard Cite

The reversible computation paradigm aims to provide a new foundation for general classical digital computing that is capable of circumventing the thermodynamic limits to the energy efficiency of the conventional, non-reversible paradigm. However, to date, the essential rationale for and analysis of classical reversible computing (RC) has not yet been expressed in terms that leverage the modern formal methods of non-equilibrium quantum thermodynamics (NEQT). In this paper, we begin developing an NEQT-based foundation for the physics of reversible computing. We use the framework of Gorini-Kossakowski-Sudarshan-Lindblad dynamics (a.k.a. Lindbladians) with multiple asymptotic states, incorporating recent results from resource theory, full counting statistics, and stochastic thermodynamics. Important conclusions include that, as expected: (1) Landauer's Principle indeed sets a strict lower bound on entropy generation in traditional non-reversible architectures for deterministic computing machines when we account for the loss of correlations; and (2) implementations of the alternative reversible computation paradigm can potentially avoid such losses, and thereby circumvent the Landauer limit, potentially allowing the efficiency of future digital computing technologies to continue improving indefinitely. We also outline a research plan for identifying the fundamental minimum energy dissipation of reversible computing machines as a function of speed.

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“…The RFA was designed and fabricated using the AIST 10 kA cm -2 Nb high-speed standard process (HSTP) [15]. The physical layout design of the RQFP gates in the RFA was based on designs reported in the literature [16].…”

Section: Experimental Demonstrationmentioning

confidence: 99%

“…Numerical simulations [14] suggested that RQFP gates can perform logic operations in a thermodynamically reversible manner, or without energy dissipation, if RQFP gates are operated quasi-statically. Furthermore, we fabricated an RQFP gate using the Nb integrated-circuit fabrication process [15] provided by the National Institute of Advanced Industrial Science and Technology (AIST), and demonstrated its correct logic operations at liquid He temperature [16].…”

Section: Introductionmentioning

confidence: 99%

A reversible full adder using adiabatic superconductor logic

Yamae

¹

,

Takeuchi

²

,

Yoshikawa

³

2019

Supercond. Sci. Technol.

Self Cite

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Reversible logic circuits can perform logic operations in a thermodynamically reversible manner, or without energy dissipation. The reversible quantum-flux-parametron (RQFP) is a reversible logic gate using adiabatic superconductor logic. In the present study, we design and demonstrate a reversible full adder (RFA) using RQFP gates in order to demonstrate that RQFP gates can be used as building blocks to design reversible logic circuits. An analysis of the time evolution of the phase differences across the Josephson junctions in the RFA showed that its logic state can change quasi-statically during a logic operation. Calculation of the energy dissipation of the RFA showed that it decreases in proportion to the operating frequency. These numerical calculation results ensure that the RFA is thermodynamically and logically reversible. In addition, we experimentally demonstrated correct operation of the RFA for all input data combinations. These results reveal that logic circuits designed using RQFP gates can perform reversible computing, i.e., RQFP gates can be used as building blocks of reversible logic circuits.

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Recent Progress on Reversible Quantum-Flux-Parametron for Superconductor Reversible Computing

Cited by 12 publications

References 33 publications

Quantum Foundations of Classical Reversible Computing

Quantum Foundations of Classical Reversible Computing

Quantum Foundations of Classical Reversible Computing

A reversible full adder using adiabatic superconductor logic

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