Wafer-Scale Fabrication and Room-Temperature Experiments on Graphene-Based Gates for Quantum Computation

Abstract: ): – requirements throughout surface waters of the N-limited North Pacific. Recent isotopic analysis of skeleton material from deep-sea corals near Hawaii also exhibit a decreasing trend over this time period, which has been interpreted as a signal of increasing N inputs from N2 fixation (36). However, because isotopic and stoichiometric signals of denitrification are transported from the anoxic zone into the subtropical gyre (37), the reported coral trends may originate partly from the OMZ. Any remaining signal attributable to N2 fixation would imply that the ecological niche of diazotrophs in the central gyre is uncoupled from the major N loss in the OMZ (38), and that a substantial imbalance of the Pacific N budget has persisted over the 20th century.

Abstract: This chapter is focused on nanoelectronic devices developed in the last years as the result of searching for alternative developments of the Moore’s law. We deal in this chapter with ballistic devices, negative capacitance FETs, hyper FETs, tunneling devices, phase change devices, quantum dots and memories. Many of them have in common the fact that quantum mechanics is at the foundation of their functionalities, i.e., they are quantum devices.

Abstract: A ‘field’ according to quantum pilot-wave theory (Bush 2015) and quantum field theory (QFT) (Griffiths 2009) when applied to the working of the universe is a fluid that is spread across the universe with a value taken in that space which can change in time. New observations in the fields of quantum fluid mechanics, artificial intelligence (AI) and deep learning in machines are providing us novel insights into how quantum processing, memory creation and storage work using the laws that governs the quantum world and quantum field theories. Such an understanding can be extrapolated to the workings of the mind to see if similar processes underlie the functioning of living systems. This paper hypothesizes that the construct of the mind is the resultant of chaotic system of interacting subatomic fields driven by force fields that intersperse with the quantum vacuum; a mechanism which has not yet been fully understood. We propose that this integrated phenomenon also gives rise to the subtle mechanisms that help in the formation of memories and also the structures which store these memories as reservoirs. The future of our evolution is the mind which evolves in these boundless intermingling quantum fields and their force fields within the quantum vacuum. With computers getting intelligent we are instantaneously but naively evolving our minds, and in the future, working together with these intelligent machines will augment it further. In fact, the design and working of these AI systems are resultant of the proof of the intelligence of conscious mind. This way the working of mind is always superior to those of the artificial systems that emerge from it.

Abstract: We show that a 3-port interferometer, defined by quantum point contacts in a two-dimensional electron gas, and working in the quantum Hall regime, can implement different logic gates at each port depending on the energy of charge carriers and the operating conditions In all cases the input logic states are encoded in the potentials applied on the quantum point contacts, while the output logic states are encoded in the values of the overall transmission coefficients at each port In addition, the output of such compact configurations can be reprogrammed by combining two 3-port interferometers

Abstract: Inspired by the brain’s structure, we have developed an efficient, scalable, and flexible non–von Neumann architecture that leverages contemporary silicon technology. To demonstrate, we built a 5.4-billion-transistor chip with 4096 neurosynaptic cores interconnected via an intrachip network that integrates 1 million programmable spiking neurons and 256 million configurable synapses. Chips can be tiled in two dimensions via an interchip communication interface, seamlessly scaling the architecture to a cortexlike sheet of arbitrary size. The architecture is well suited to many applications that use complex neural networks in real time, for example, multiobject detection and classification. With 400-pixel-by-240-pixel video input at 30 frames per second, the chip consumes 63 milliwatts.

Abstract: The performance of superconducting qubits has improved by several orders of magnitude in the past decade. These circuits benefit from the robustness of superconductivity and the Josephson effect, and at present they have not encountered any hard physical limits. However, building an error-corrected information processor with many such qubits will require solving specific architecture problems that constitute a new field of research. For the first time, physicists will have to master quantum error correction to design and operate complex active systems that are dissipative in nature, yet remain coherent indefinitely. We offer a view on some directions for the field and speculate on its future.

Abstract: Devices made from graphene encapsulated in hexagonal boron-nitride exhibit pronounced negative bend resistance and an anomalous Hall effect, which are a direct consequence of room-temperature ballistic transport at a micrometer scale for a wide range of carrier concentrations. The encapsulation makes graphene practically insusceptible to the ambient atmosphere and, simultaneously, allows the use of boron nitride as an ultrathin top gate dielectric.

Abstract: This review describes recent groundbreaking results in Si, Si/SiGe, and dopant-based quantum dots, and it highlights the remarkable advances in Si-based quantum physics that have occurred in the past few years. This progress has been possible thanks to materials development of Si quantum devices, and the physical understanding of quantum effects in silicon. Recent critical steps include the isolation of single electrons, the observation of spin blockade, and single-shot readout of individual electron spins in both dopants and gated quantum dots in Si. Each of these results has come with physics that was not anticipated from previous work in other material systems. These advances underline the significant progress toward the realization of spin quantum bits in a material with a long spin coherence time, crucial for quantum computation and spintronics.

Abstract: Graphene nanoribbons will be essential components in future graphene nanoelectronics. However, in typical nanoribbons produced from lithographically patterned exfoliated graphene, the charge carriers travel only about ten nanometres between scattering events, resulting in minimum sheet resistances of about one kilohm per square. Here we show that 40-nanometre-wide graphene nanoribbons epitaxially grown on silicon carbide are single-channel room-temperature ballistic conductors on a length scale greater than ten micrometres, which is similar to the performance of metallic carbon nanotubes. This is equivalent to sheet resistances below 1 ohm per square, surpassing theoretical predictions for perfect graphene by at least an order of magnitude. In neutral graphene ribbons, we show that transport is dominated by two modes. One is ballistic and temperature independent; the other is thermally activated. Transport is protected from back-scattering, possibly reflecting ground-state properties of neutral graphene. At room temperature, the resistance of both modes is found to increase abruptly at a particular length--the ballistic mode at 16 micrometres and the other at 160 nanometres. Our epitaxial graphene nanoribbons will be important not only in fundamental science, but also--because they can be readily produced in thousands--in advanced nanoelectronics, which can make use of their room-temperature ballistic transport properties.