Since many underlying quantum algorithms include a Boolean component, synthesis of the respective circuits is often conducted by a two-stage procedure: First, a reversible circuit realizing the Boolean component is generated. Afterwards, this circuit is mapped into a respective quantum gate cascade. In addition, recent physical accomplishments have led to further issues to be considered, e.g. n...

Quantum circuit is generalized to include non-unitary gates which are operated by quantum measurement. A 1-qubit non-unitary gate, together with the controlled-NOT gate and the 1-qubit unitary gate, is shown to constitute a universal set of gates for the non-unitary quantum circuit that reduces the number of the overhead of qubits required to ensure fault tolerance. A reversing measurement sche...

We consider a unitary transformation which maps any given state of an n-qubit quantum register into another one. This transformation has applications in the initialization of a quantum computer, and also in some quantum algorithms. Employing uniformly controlled rotations, we present a quantum circuit of 2 − 4n − 4 CNOT gates and 2 − 5 one-qubit elementary rotations that effects the state trans...

We investigate the quantum photovoltaic effect in double quantum dots by applying the nonequilibrium quantum master equation. A drastic suppression of the photovoltaic current is observed near the open circuit voltage, which leads to a large filling factor. We find that there always exists an optimal inter-dot tunneling that significantly enhances the photovoltaic current. Maximal output power ...

Quantum computation constitutes a rapidly expanding subfield of computer science. Development quantum algorithms is facilitated by the availability of efficient quantum programming languages, and a plethora of approaches has been already suggested in the literature, ranging from GUI-based simple tools to elaborate standalone programming languages. In this paper we propose a novel paradigm calle...

We experimentally demonstrate and characterize a four-qubit linear-optical quantum logic circuit. Our robust and versatile scheme exploits encoding of two qubits into polarization and path degrees of single photons and involves two crossed inherently stable interferometers. This approach allows us to design a complex quantum logic circuit that combines a genuine four-qubit C(3)Z gate and severa...

Several promising implementations of quantum computation rely on a Linear Nearest Neighbor (LNN) architecture, which arranges quantum bits on a line, and allows neighbor interactions only. Therefore, several specific circuits have been designed on an LNN architecture. However, a general and efficient conversion method for an arbitrary circuit has not been established. Therefore, this paper give...

The quantum circuit is generalized to include non-unitary gates operated by quantum measurement, in order to reduce the number of the overhead of qubits required to ensure fault tolerance. A specific type of one-qubit non-unitary gates, together with the controlled-not gate and all one-qubit unitary gates, is shown to constitute a universal set of gates for the non-unitary quantum circuit. A re...

In this work we applied a quantum circuit treatment to describe the nuclear spin relaxation. From the Redfield theory, we were able to describe the quadrupolar relaxation as a computational process in the case of spin 3/2 systems, through a model in which the environment is comprised by five qubits and three different quantum noise channels. The interaction between the environment and the spin ...