In one-way quantum computation (1WQC) model, universal quantum computations are performed using measurements to designated qubits in a highly entangled state. The choices of basis for these measurements as well as the structure of the entanglements specify a quantum algorithm. Although a number of methods have been proposed to simulate quantum circuit model on classical computers, no efficient tool has been developed to simulate the 1WQC model directly. In this paper, some techniques such as qubit elimination, implicit and in-place matrix-vector multiplication and pattern reordering are utilized to considerably reduce the time and memory needed for the simulations. These techniques were implemented in a tool called One-Way Quantum computation Simulator (OWQS). Experimental results validate the efficiency of the proposed approach.
In one-way quantum computation (1WQC) model, universal quantum computations are performed using measurements to designated qubits in a highly entangled state. The choices of basis for these measurements as well as the structure of the entanglements specify a quantum algorithm. Although a number of methods have been proposed to simulate quantum circuit model on classical computers, no efficient tool has been developed to simulate the 1WQC model directly. In this paper, some techniques such as qubit elimination, implicit and in-place matrix-vector multiplication and pattern reordering are utilized to considerably reduce the time and memory needed for the simulations. These techniques were implemented in a tool called One-Way Quantum computation Simulator (OWQS). Experimental results validate the efficiency of the proposed approach.
In one-way quantum computation (1WQC) model, universal quantum computations are performed using measurements to designated qubits in a highly entangled state. The choices of bases for these measurements as well as the structure of the entanglements specify a quantum algorithm. As scalable and reliable quantum computers have not been implemented yet, quantum computation simulators are the only widely available tools to design and test quantum algorithms. However, simulating the quantum computations on a standard classical computer in most cases requires exponential memory and time. In this paper, a general direct simulator for 1WQC, called OWQS, is presented. Some techniques such as qubit elimination, pattern reordering and implicit simulation of actions are used to considerably reduce the time and memory needed for the simulations. Moreover, our simulator is adjusted to simulate the measurement patterns with a generalized flow without calculating the measurement probabilities which is called extended one-way quantum computation simulator (EOWQS). Experimental results validate the feasibility of the proposed simulators and that OWQS and EOWQS are faster as compared with the well-known quantum circuit simulators, i.e., QuIDDPro and libquantum for simulating 1WQC model.
In the one-way quantum computation (1WQC) model, computations are done by correlated sequences of entanglement, measurement and local corrections commands. As scalable and reliable quantum computers have not been implemented yet, the only widely available tools for designing and testing quantum algorithms are quantum computation simulators. However, simulating quantum computations on a standard classical computer in most cases requires very large memory and time. Recently, an array-based simulator, called one-way quantum computation simulator (OWQS) has been proposed to directly simulate the 1WQC model. OWQS outperforms the previously proposed quantum computation simulators to simulate the 1WQC model. In this paper, OWQS is modified in a way that it utilizes the graph-based representation of system states using algebraic decision diagram (ADD) in order to benefit from the similarities in the quantum states of 1WQC. This simulator is called graph-based OWQS, GOWQS. Experimental results validate the considerable improvement of the proposed simulator as compared to OWQS.
In one-way quantum computations (1WQC), quantum correlations in an entangled state, called a cluster or graph state, are exploited to perform universal quantum computations using single-qubit measurements. The choices of bases for these measurements as well as the structure of the entanglements specify a quantum algorithm. The needed computations in this model are organized as patterns. Previously, an approach to extract a 1WQC pattern from a quantum circuit was proposed. The approach takes a quantum circuit consisting of only CZ andj(oc) gates and translates it into a 1WQC pattern after performing some known optimizations. However, most quantum synthesis algorithms decompose circuits using a library containing CNOT and any single-qubit gates. In this paper, we show how this approach can be modified in a way that it can take a circuit consisting of CNOT and any single-qubit gates as well as CZ and J(oc) gates to produce a 1WQC pattern. Experimental results show that adding CNOT gate directly to the pattern decreases the translation run-time.
One-way quantum computation (1WQC) is a model of universal quantum computations in which a specific highly entangled state called acluster stateallows for quantum computation by single-qubit measurements. The needed computations in this model are organized as measurement patterns. The traditional approach to obtain a measurement pattern is by translating a quantum circuit that solely consists of CZ andJ(α) gates into the corresponding measurement patterns and then performing some optimizations by using techniques proposed for the 1WQC model. However, in these cases, the input of the problem is a quantum circuit, not an arbitrary unitary matrix. Therefore, in this article, we focus on the first phase—that is, decomposing a unitary matrix into CZ andJ(α) gates. Two well-known quantum circuit synthesis methods, namely cosine-sine decomposition and quantum Shannon decomposition are considered and then adapted for a library of gates containing CZ andJ(α), equipped with optimizations. By exploring the solution space of the combinations of these two methods in a bottom-up approach of dynamic programming, a multiobjective quantum circuit synthesis method is proposed that generates a set of quantum circuits. This approach attempts to simultaneously improve the measurement pattern cost metrics after the translation from this set of quantum circuits.
Quantum computing allows the realization of certain tasks more efficiently than its classical counterpart. This monograph seeks to present a type of quantum computation that is different from the standard form: Measurement-Based Quantum Computation, more specifically a model known as One-Way Quantum Computation (1WQC), developed by R. Raussendorf and H. Briegel. To understand it, this work starts from the circuit model, the most common type of quantum computing, describing its main components. The 1WQC model is then introduced, with an attempt to didactically present its operation. A way of applying one- and two-qubit quantum logic gates is also shown, thus explaining how universal quantum computing is possible in this model. As an example, the translation of Deutsch’s algorithm to this model is also discussed. The result of this operation raises, however, open questions concerning the translation of Oracle-type algorithms, such as Deutsch’s, to the 1WQC model
In the formalism of measurement based quantum computation we start with a given fixed entangled state of many qubits and perform computation by applying a sequence of measurements to designated qubits in designated bases. The choice of basis for later measurements may depend on earlier measurement outcomes and the final result of the computation is determined from the classical data of all the measurement outcomes. This is in contrast to the more familiar gate array model in which computational steps are unitary operations, developing a large entangled state prior to some final measurements for the output. Two principal schemes of measurement based computation are teleportation quantum computation (TQC) and the so-called cluster model or one-way quantum computer (1WQC). We will describe these schemes and show how they are able to perform universal quantum computation. We will outline various possible relationships between the models which serve to clarify their workings. We will also discuss possible novel computational benefits of the measurement based models compared to the gate array model, especially issues of parallelisability of algorithms.