CALA-
n: A Quantum Library for Realizing Cost-Effective 2-, 3-, 4-, and 5-bit Gates on IBM Quantum Computers using Bloch Sphere Approach, Clifford+T Gates, and Layouts
We introduce a new quantum layout-aware approach to realize cost-effective
n-bit gates using the Bloch sphere, for
2≤n≤5 qubits. These
n-bit gates are entirely constructed from the Clifford+T gates, in the approach of selecting sequences of rotations visualized on the Bloch sphere. This Bloch sphere approach ensures to match the quantum layout for synthesizing (transpiling) these
n-bit gates into an IBM quantum computer. Various standard
n-bit gates (Toffoli, Fredkin, etc.) and their operational equivalent of our proposed
n-bit gates are examined and evaluated, in the context of the final quantum costs, as the final counts of generated IBM native gates. In this paper, we demonstrate that all our
n-bit gates always have lower quantum costs than those of standard
n-bit gates after transpilation. Hence, our Bloch sphere approach can be used to build a quantum library of various cost-effective
n-bit gates for different layouts of IBM quantum computers.
A cost-effective n-bit Toffoli gate is proposed to be realized (or transpiled) based on the layouts (linear, T-like, and I-like) and the number of n physical qubits for IBM quantum computers. This proposed gate is termed the "layout-aware n-bit Toffoli gate". The layout-aware n-bit Toffoli gate is designed using the visual approach of the Bloch sphere, from the visual representations of the rotational quantum operations for IBM native gates. In this paper, we also proposed a new formula for the quantum cost, which calculates the total number of native gates, the crossing connections, and the depth of the final transpiled quantum circuit. This formula is termed the "transpilation quantum cost". After transpilation, our proposed layout-aware n-bit Toffoli gate always has a much lower transpilation quantum cost than that of the conventional n-bit Toffoli gate, where 3 <= n <= 7 qubits, for different IBM quantum computers.
Abstract Reversible gates have been one of the emerging research areas in these days. The reversible gates have several applications in the fields of low power CMOS, DNA computing, optical, nanotechnology etc. Quantum computing is one of the fastest and upcoming nanotechnologies that can implement the digital logical circuits using reversible logic gates. In this paper, CNOT, TOFFOLI, FREDKIN and PERES reversible logic gates have been implemented on IBM quantum computer. An efficient one-bit full adder is going to be proposed using the reversible gates like CNOT and TOFFOLI. Later, a 4x4 multiplier will be developed using the proposed one-bit full adder. The proposed multiplier is proved to perform faster calculations compared to the earlier multipliers. The simulation of the presented modules will be done on IBM Quantum computer and the respective probabilities can be observed for different inputs.