1. Current OTDM Component Technology The large and ultrafast optical nonlinearity of millimeter-size semiconductor optical amplifiers (SOAs) has led to the study of several types of gate functions at ultrahigh bit-rates beyond 40 Gb/s. Among these functions, optical demultiplexing has been the most successfully demonstrated with 336 Gb/s RZ signals [1]. The slow-recovery-induced phenomena that ...

We introduce a Cooper pair "sluice" for the implementation of a frequency-locked current source. The device consists of two mesoscopic SQUIDs and of a single superconducting island with a gate. We demonstrate theoretically that it is possible to obtain a current as high as 0.1 nA at better than ppm accuracy via periodically modulating both the gate charge and the effective Josephson coupling. W...

We have previously 11] shown that for quantum memories and quantum communication, a state can be transmitted over arbitrary distances with error provided each gate has error at most cc. We discuss a similar concatenation technique which can be used with fault tolerant networks to achieve any desired accuracy when computing with classical initial states, provided a minimum gate accuracy can be a...

A novel universal and fault-tolerant basis (set of gates) for quantum computation is described. Such a set is necessary to perform quantum computation in a realistic noisy environment. The new basis consists only of two single-qubit gates (Hadamard and σ 1/4 z ), and one two-qubit gate (Controlled-NOT). Moreover, a new general method for fault-tolerant implementation of quantum gates like Toffo...

Error-correcting codes protect quantum information and form the basis of fault-tolerant quantum computing. Leading proposals for fault-tolerant quantum computation require codes with an exceedingly rare property, a transversal non-Clifford gate. Codes with the desired property are presented for d-level qudit systems with prime d. The codes use n=d-1 qudits and can detect up to ∼d/3 errors. We q...

The novel 2xVDD NOT, NAND, and NOR logic gates have been designed and implemented in a nanoscale CMOS process with only 1xVDD devices. With the proposed dynamic source bias technique, the logic gates can be designed to have 2xVDD tolerant capability. Thus, the new 2xVDD logic gates can be operated under 2xVDD voltage environment without suffering the gate-oxide reliability issue.

How important is fast measurement for fault-tolerant quantum computation? Using a combination of existing and new ideas, we argue that measurement times as long as even 1000 gate times or more have a very minimal effect on the quantum accuracy threshold. This shows that slow measurement, which appears to be unavoidable in many implementations of quantum computing, poses no essential obstacle to...

We derive a threshold result for fault-tolerant quantum computation for local non-Markovian noise models. The role of error amplitude in our analysis is played by the product of the elementary gate time t0 and the spectral width of the interaction Hamiltonian between system and bath. We discuss extensions of our model and the applicability of our analysis for several physical decoherence proces...

Exploiting recent advances in quantum trapped-ion technologies, we propose a scalable, fault-tolerant quantum computing architecture that overcomes the fundamental challenges of building a full-scale quantum computer and leaves the fabrication a daunting but primarily an engineering concern. Using a hierarchical array-based design and a quantum teleportation communication protocol, we are able ...

This work compares the overhead of quantum error correction with concatenated and topological quantum error-correcting codes. To perform a numerical analysis, we use the Quantum Resource Estimator Toolbox (QuRE) that we recently developed. We use QuRE to estimate the number of qubits, quantum gates, and amount of time needed to factor a 1024-bit number on several candidate quantum technologies ...