Quantum computing

Open Access Article

1 - Automated Implementation of Quantum Circuits on QFPGA for Emulation
M. Heidarzadeh Mohammad Danaee Far

20.1001.1.16823745.1392.11.4.1.8

This paper defines an optimal architecture for the FPGA using exact methods. In order to achieve this goal, optimal placement and routing solutions are found using the integer linear programming techniques. After redefining the internal architecture of the logic blocks, More

This paper defines an optimal architecture for the FPGA using exact methods. In order to achieve this goal, optimal placement and routing solutions are found using the integer linear programming techniques. After redefining the internal architecture of the logic blocks, quantum circuits are partitioned by a heuristic algorithm in order to reach maximum utilization of the resources inside logic blocks and minimum delay of the paths traversed by the q-bits in the circuit. Experimental results show that FPGA architecture modifications can result in the reduction of the delay of critical paths of circuits by up to half in some cases and in a considerable reduction of the number of channels used for routing. Furthermore, the results show that defining the logic blocks with 12 q-bits instead of 4 q-bits can decrease circuits delay and the number of used channels to a large extent. Manuscript profile

Open Access Article

2 - Quantum-Logic Synthesis Using Improved Block-Based Approach
K. Marjoei M. Houshmand M. Saheb Zamani M. Sedighi

20.1001.1.16823745.1395.14.3.14.0

Quantum-logic synthesis refers to generating a quantum circuit for a given arbitrary quantum gate according to a specific universal gate library implementable in quantum technologies. Previously, an approach called block-based quantum decomposition (BQD) has been propos More

Quantum-logic synthesis refers to generating a quantum circuit for a given arbitrary quantum gate according to a specific universal gate library implementable in quantum technologies. Previously, an approach called block-based quantum decomposition (BQD) has been proposed to synthesize quantum circuits by using a combination of two well-known quantum circuit synthesis methods, namely, quantum Shannon decomposition (QSD) and cosine-sine decomposition (CSD). In this paper, an improved block-based quantum decomposition (IBQD) is proposed. IBQD is a parametric approach and explores a larger space than CSD, QSD, and BQD to obtain best results for various synthesis cost metrics. IBQD cost functions for synthesis are calculated in terms of different synthesis cost metrics with respect to the parameters of the proposed approach. Furthermore, in order to find optimum results according to these functions, IBQD synthesis approach is defined as a constrained-optimization model. The results show that IBQD can lead to the minimum total gate cost among all the proposed approaches for the specific case of 4-qubit quantum circuit synthesis. Moreover, for the first time, the depth costs of the CSD, QSD, BQD, and IBQD synthesis approaches are evaluated and it is shown that IBQD makes a trade-off between the total gates and depth costs for the synthesized quantum circuits. Manuscript profile

Open Access Article

3 - Optimizing Quantum Circuits by One-Way Quantum Computation Model Based on Pattern Geometries
M. Eslamy M. Saheb Zamani M. Sedighi M. Houshmand

20.1001.1.16823745.1395.14.4.10.8

A fundamentally quantum model of computation based on quantum entanglement and quantum measurement is called one-way quantum computation model (1WQC). Computations are shown by measurement patterns (or simply patterns) in this model where an initial highly entangled sta More

A fundamentally quantum model of computation based on quantum entanglement and quantum measurement is called one-way quantum computation model (1WQC). Computations are shown by measurement patterns (or simply patterns) in this model where an initial highly entangled state called a graph state is used to perform universal quantum computations. This graph together with the set of its input and output qubits is called the geometry of the pattern. Moreover, some optimization techniques have been introduced to simplify patterns. Previously, the 1WQC model has been applied to optimize quantum circuits. An approach for parallelizing quantum circuits has been proposed which takes a quantum circuit and then produces the corresponding pattern after performing the proposed optimization techniques for this model. Then it translates the optimized 1WQC patterns back to quantum circuits to parallelize the initial quantum circuit by using a set of rewriting rules. To improve previous works, in this paper, a new automatic approach is proposed to optimize patterns based on their geometries instead of using rewriting rules by applying optimization techniques simultaneously. Moreover, the optimized pattern is translated back to a quantum circuit and then this circuit is simplified by decreasing the number of auxiliary qubits. Results show that the quantum circuit cost metrics of the proposed approach is improved as compared to the previous ones. Manuscript profile

Open Access Article

4 - Design of Parity Preserving Reversible Signed Multiplier Circuit
M. Haghparast A. Bolhassani

20.1001.1.16823745.1397.16.3.8.8

One of the major challenges and constraints in designing very large integrated circuits is the power dissipation of transistors. Reversible logic is one of the new paradigm in reducing the power consumption of digital circuits in the quantum computing field. In this pap More

One of the major challenges and constraints in designing very large integrated circuits is the power dissipation of transistors. Reversible logic is one of the new paradigm in reducing the power consumption of digital circuits in the quantum computing field. In this paper, an improved design of a parallel 5-bit parity preserving reversible signed multiplier circuit is presented. Reversible circuit designs with parity preserving property are an important issue for the implementation of fault tolerant systems in nanotechnology area. To design of the proposed multiplier, the reversible full adder circuit using 5×5 reversible HBF block with low quantum cost, and the 4×4 reversible HBL gate, with parity preserving property are proposed. The structure of the multiplier circuit consists of two parts of the partial product generation (PPG) and multi-operand addition (MOA). This structure is based on Baugh-Wooley and Wallace-Tree algorithms, which results in improved speed of operation in a 5-bit multiplier for signed digits. The proposed circuits are optimized based on important evaluation issues such as quantum cost, garbage outputs and constant inputs, and also are compared with the existing circuits. The main goal is to reduce the quantum cost, the number of constant inputs and garbage outputs in the design of the proposed multiplier circuit. The results of the final evaluation and comparison shows that the proposed multiplier in this study is improved by 26% in quantum cost, 9% in garbage outputs and 9% in constant inputs relative to the best existing designs. Manuscript profile

Open Access Article

5 - Multi-Objective Logic Synthesis of Quantum Circuits
Arezoo Rajaei Mahboobeh Houshmand Seyyed Abed Hosseini

20.1001.1.16823745.1401.20.3.6.4

Quantum computing is a new method of information processing that is based on the concepts of quantum mechanics and leads to strange and powerful events in the quantum field. The logic synthesis of quantum circuits refers to the process of converting a given quantum gate More

Quantum computing is a new method of information processing that is based on the concepts of quantum mechanics and leads to strange and powerful events in the quantum field. The logic synthesis of quantum circuits refers to the process of converting a given quantum gate into a set of gates that can be implemented in quantum technologies. The most famous logic synthesis methods are CSD and QSD. The main goal of this study is to present a multi-objective logical synthesis method combining the above two methods in the quantum circuit model with the aim of optimizing the evaluation criteria. In this proposed method, the solution space is created from different combinations of CSD and QSD decomposition methods. The created solution space is a space with a very large exponential size. Then, using a bottom-up approach of multi-objective dynamic programming, a method is presented to search only a part of the entire solution space to find circuits with the optimal Pareto costs. The obtained results show that this method creates a balance between the evaluation criteria and produces many optimal Pareto solutions that can be selected according to different quantum technologies. Manuscript profile

Open Access Article

6 - A Two-Level Method Based on Dynamic Programming for Partitioning and Optimization of the Communication Cost in Distributed Quantum Circuits
zohreh davarzani maryam zomorodi-moghadam M. Houshmand

Nowadays, quantum computing has played a significant role in increasing the speed of algorithms. Due to the limitations in the manufacturing technologies of quantum computers, the design of a large-scale quantum computer faces many challenges. One solution to overcome t More

Nowadays, quantum computing has played a significant role in increasing the speed of algorithms. Due to the limitations in the manufacturing technologies of quantum computers, the design of a large-scale quantum computer faces many challenges. One solution to overcome these challenges is the design of distributed quantum systems. In these systems, quantum computers are connected to each other through the teleportation protocol to transfer quantum information. Since quantum teleportation requires quantum resources, it is necessary to reduce the number of that. The purpose of this paper is to present a distributed quantum system considering the two goals of balanced distribution of qubits and minimizing the number of teleportation protocols in two levels. In the first level, by presenting a dynamic programming algorithm, an attempt has been made to distribute qubits in a balanced manner and reduce the number of connections between subsystems. According to the output partitioning obtained from the first level, in the second level and in the stage of implementation of global gates, when one of the qubits of this gate is teleported from the home to the desired destination, this qubit may be able to be used by a number of global gates, observing the precedence restrictions and as a result it reduces the number of teleportations. The obtained results show the better performance of the proposed algorithm. Manuscript profile

Open Access Article

7 - Optimization of Initial States for Adiabatic Quantum Computing in a Quantum Algorithm
Arash Karimkhani Amir Ghal’e

In any adiabatic quantum computation, there exist an initial state that must be used in the corresponding quantum algorithm. In this paper, the relation between an initial state and allowed energy level of an implemented generalized Deutsch’s algorithm is investigated. More

In any adiabatic quantum computation, there exist an initial state that must be used in the corresponding quantum algorithm. In this paper, the relation between an initial state and allowed energy level of an implemented generalized Deutsch’s algorithm is investigated. To study the generalized Deutsch’s algorithm, a compacted form for the output states of the algorithm is obtained. It has been shown that one can prepare the initial states in such a way that control the minimum of energy. By using numerical methods, the minimum values of allowed energy levels for the initial state are obtained. Also, to study the dynamics of the system is chosen. The corresponding Hamiltonian for the algorithm is obtained and it has been shown that one of the energy levels describes a binding state. Manuscript profile

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