Jonathan A. Jones, Vlatko Vedral, Artur Ekert and Giuseppe Castagnoli Centre for Quantum Computation, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK OCMS, New Chemistry Laboratory, South Parks Road, Oxford OX1 3QT, UK Elsag,Via Puccini 2, 1615 Genova, Italy (February 29, 2008) An exciting recent development has been the discovery that the computational power of quantum computers exceeds t...

Quantum computation provides great speedup over its classical counterpart for certain problems. One of the key challenges for quantum computation is to realize precise control of the quantum system in the presence of noise. Control of the spin-qubits in solids with the accuracy required by fault-tolerant quantum computation under ambient conditions remains elusive. Here, we quantitatively chara...

Most industrial digital circuits contain three-state elements besides pure logic gates. This paper presents a gate delay fault simulator for combinational circuits that can handle three-state elements like bus drivers, transmission gates and pulled busses. The well known delay faults − "slow-to-rise" and "slow-to-fall" − are considered as well as delayed transitions from isolating signal state ...

Entangling a single spin to the polarization of a single incoming photon, generated by an external source, would open new paradigms in quantum optics such as delayed-photon entanglement, deterministic logic gates or fault-tolerant quantum computing. These perspectives rely on the possibility that a single spin induces a macroscopic rotation of a photon polarization. Such polarization rotations ...

In this paper we are going to explore low-level implementation issues for fault-tolerant adders based on multiplexing using majority gates (MAJ). We shall analyze the particular case of a 32-bit ripple carry adder (RCA), as well as different redundant designs using MAJ-3 (MAJ of fan-in 3) multiplexed RCAs: (i) with classical MAJ-3 gates in the restorative stages; (ii) with inverters driven by s...

There are many distributed systems which use a leader in their logic. When such systems need to be fault tolerant and the current leader suffers a technical problem, it is necesary to apply a special algorithm in order to choose a new leader. In this paper I present a new fault tolerant algorithm which elects a new leader based on a random roulette wheel selection.

Gene regulatory networks (GRNs) form naturally predefined and optimised computational units envisioned to act as biohardware able to solve hard computational problems efficiently. This interplay of GRNs via signalling pathways allows the consideration as well as implementation of interconnection-free and fault tolerant programmable computing agents. It has been quantitatively shown in an in viv...

Errors in quantum computers can be classified into two classes: the static errors—decoherence in qubits arising from the interaction between computational qubits and the environment—and the dynamical errors—imperfection of logic operations arising from the interaction between computational qubits and controllers of quantum gates. The current theory of fault-tolerant quantum computing concludes ...

This pedagogical review presents the proof of the Solovay-Kitaev theorem in the form of an efficient classical algorithm for compiling an arbitrary single-qubit gate into a sequence of gates from a fixed and finite set. The algorithm can be used, for example, to compile Shor's algorithm, which uses rotations of π/2 k , into an efficient fault-tolerant form using only Hadamard, controlled-not, a...

In 2014, Lloyd and Montangero have made a brief research proposal on universal quantum computation in integrable systems. The main idea is to encode qubits into action variables build up gates by the method of resonant control. We study this argue using as fault-tolerant computation, whose fault tolerance guaranteed KAM theorem. Besides, we view Birkhoff norm form mathematical framework extende...