Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
Applications of nanophotonics to classical and quantum information technology
Raymond G. Beausoleil, David A. Fattal, Marco Fiorentino B, Charles Santori, Gregory L. Snider, S. M. Spillane, Richard Stanley Williams, William J. Munro, Timothy P. Spiller, J. R. Rabeau, Steven Prawer, Fedor Jelezko, Philippe Tamarat, Jörg Wrachtrup, Philip Hemmer
Moore's Law has set great expectations that the performance/price ratio of commercially available semiconductor devices will continue to improve exponentially at least until the end of the next decade. Although the physics of nanoscale silicon transistors alone would allow these expectations to be met, the physics of the metal wires that connect these transistors will soon place stringent limits on the performance of integrated circuits. We will describe a Si-compatible global interconnect architecture - based on chip-scale optical wavelength division multiplexing - that could precipitate an "optical Moore's Law" and allow exponential performance gains until the transistors themselves become the bottleneck. Based on similar fabrication techniques and technologies, we will also present an approach to an optically-coupled quantum information processor for computation beyond Moore's Law, encouraging the development of practical applications of quantum information technology for commercial utilization. We present recent results demonstrating coherent population trapping in single N-V diamond color centers as an important first step in this direction.
Moore's Law has set great expectations that the performance/price ratio of commercially available semiconductor devices will continue to improve exponentially at least until the end of the next decade. Although the physics of nanoscale silicon transistors alone would allow these expectations to be met, the physics of the metal wires that connect these transistors will soon place stringent limits on the performance of integrated circuits. We will describe a Si-compatible global interconnect architecture - based on chip-scale optical wavelength division multiplexing - that could precipitate an "optical Moore's Law" and allow exponential performance gains until the transistors themselves become the bottleneck. Based on similar fabrication techniques and technologies, we will also present an approach to an optically-coupled quantum information processor for computation beyond Moore's Law, encouraging the development of practical applications of quantum information technology for commercial utilization. We present recent results demonstrating coherent population trapping in single N-V diamond color centers as an important first step in this direction.
The capability of realizing quantum photonics implementations on-chip will have a strong impact on several aspects of quantum computation and information processing. The implementation of large scale integrated quantum photonic technologies requires on-chip reconfigurable waveguide circuits as well as single-photon sources and detectors. Many successes have been made in recent years to demonstrate complex quantum circuits in many material platforms. Among all these platforms, the Silicon-on-Insulator (SOI) platform is outstanding as it is well developed for classical applications and therefore deploys a high component density, mature fabrication techniques and compatibility with the telecom regime and the complementary metal-oxide-semiconductor (CMOS) technology. However, the lack of on-demand non-classical light sources, directly incorporated in silicon chips, forces the use of nonlinear processes to generate non-classical light states: the probabilistic nature of the emission process sets a limit in the maximally achievable experimental complexity. The use of on-demand sources will have a strong impact on the device’s scalability.
Chip-scale integrated photonic circuits provide an attractive platform for the implementation of many quantum photonic technologies ranging from precise metrology to secure communication and quantum computation. In particular, silicon photonic platforms support micron-scale nonlinear optical sources of non-classical light which can be mass manufactured using the robust fabrication processes pioneered by the CMOS microelectronics industry. Integration of these quantum photonic sources with high-performance classical photonic devices on the same chip is required for truly scalable quantum information technologies. Integrated nonlinear resonators are investigated as sources of quantum mechanically correlated photon pair sources. An all-order dispersion engineering method is presented as a robust design synthesis for micoring sources. In addition, a novel concept of coupled mode dispersion compensation is proposed and demonstrated, providing significantly improved performance characteristics of resonant four-wave mixing sources. Next a photon pair source is demonstrated in a commercial CMOS microelectronics process opening the door to future integration of quantum photonics with electronic logic and control circuits. Classical nonlinear optical measurements of stimulated four-wave mixing are used for the first time to accurately predict the quantum correlations from the same device operating in the photon pair regime. Next the first demonstration of fully on-chip pump rejection is demonstrated with over 95 dB pump extinction improving the figures of merit from previous demonstrations by multiple orders of magnitude, including losses, detected pair rates and size. Finally, proposals for introducing novel degrees of freedom provided by an integrated platform are presented for further improving the performance of both photon pair and classical nonlinear optical sources.
Moore's Law, doubling the number of transistors in a chip every two years, has contributed to the evolution of computer system architectures to date. The growth of such hardware implementation makes many optimization opportunities available to software developers. Unfortunately, we cannot expect sustainable transistor shrinking anymore; that is, the end of Moore's Law will come. Although device and manufacturing technologies continue to progress, some researchers predict that transistor shrinking may stop around 2030 to 2035 due to physical or economic reasons. The goal of this research is to open the door for post-CMOS ultrahigh-performance, low-power computing. Our approach is based on device/circuit/architecture-level co-designs by targeting an emerging device called the single-flux quantum (SFQ). We have successfully demonstrated several outstanding physical designs supporting over 30 GHz. This paper summarizes our research outcomes and discusses the future direction of next-generation computer system architecture.
Q uantum mechanics has had an enormous technological and societal impact.To grasp this point, it is sufficient to cite the invention of the transistor, perhaps the most remarkable among the countless other applications of quantum mechanics.It is also easy to see the enormous impact of computers on everyday life.The importance of computers is such that it is appropriate to say that we are now living in the information age.This information revolution became possible thanks to the invention of the tran sistor, that is, thanks to the synergy between computer science and quantum physics.Today this synergy offers completely new opportunities and promises exciting advances in both funda mental science and technological application.We are referring here to the fact that quantum mechanics can be used to process and transmit information [1,2].Miniaturization provides us with an intuitive way of under standing why, in the near future, quantum laws will become important for computation.The electronics industry for com puters grows hand-in-hand with the decrease in size of integrated circuits.This miniaturization is necessary to increase computa tional power, that is, the number of floating-point operations per second (flops) a computer can perform.In the 1950's, electronic computers based on vacuum-tube technology were capable of performing approximately 103 floating-point operations per second, while nowadays there exist supercomputers whose power is greater than lOteraflops (1013 flops).As we have remarked, this enormous growth of computational power has been made possi ble owing to progress in m in ia tu riz a tio n , w hich m ay be quantified empirically in Moore's law.This law is the result of a remarkable observation made by Gordon Moore in 1965: the number of transistors on a single integrated-circuit chip doubles approximately every 18 24 months.This exponential growth has not yet saturated and Moore's law is still valid.At the present time the limit is approximately 108 transistors per chip and the typical size of circuit components is of the order of 100 nanometres.Extrapolating Moore's law, one would estimate that around the year 2020 we shall reach the atomic size for storing a single bit of inform atio n .At th a t p o in t, q u a n tu m effects will becom e unavoidably dominant.One should be aware that, besides quantum effects, other fac tors could bring Moore's law to an end.In the first place, there are economic considerations.Indeed, the cost of building fabri cation facilities to m an u factu re chips has also increased exponentially with time.Nevertheless, it is important to under stand the ultimate limitations set by quantum mechanics.Even though we might overcome economic barriers by means of tech nological breakthroughs, quantum physics sets fundamental limitations on the size of the circuit components.The first ques tion under debate is whether it would be more convenient to push References
It would be difficult to overestimate the level of attention being paid worldwide to quantum information processing, and anticipated advantages it may offer to a wide variety of pursuits in engineering, technology, and basic science. Futurists muse on the wondrous possibilities and theorists formulate actual algorithms for advanced computing not possible with classical computing machines, if only there were scalable quantum computers. Further, several groups have performed compelling experiments related to quantum teleportation and quantum key distribution – both essential pieces for quantum cryptography. Still, it is a very challenging hardware problem to design architectures that support, appropriately protect, route, and process qubits to function as universal logic gates. To date, most of the optical successes toward this goal have been in bulk media, which is not easily scalable to carry out the required degree quantum error correction. In this talk, I will discuss a couple of the proposals that my collaborators at the Air Force Research Laboratory, at the Rochester Institute of Technology, and I have made toward addressing the issue, among others, of scalability. Further, thanks to the inception of the AIM Photonics Initiative, I will talk briefly about experimental tests that we have started and others that we have planned for assessing in situ the effectiveness of the devices that we have analyzed theoretically.