Reversible logic is gaining significant consideration as the potential logic design style for implementation in modern nanotechnology and quantum computing with minimal impact on physical entropy. Recent advances in reversible logic allow schemes for computer architectures using improved quantum computer algorithms. We present a VHDL behavioral model for the design and simulation of the quantum interactions of qubits in theoretical reversible logic structures. Modeling IQ gates, as opposed to only Control-V gates or Toffoli gates, allows for a more robust model that more accurately reflects a theoretical reversible computing structure. This method is an extension to existing programming language and modeling method that allows for reversible logic structures to be designed, simulated, and verified. To the best of our knowledge, this is the first work in the behavioral model of integrated qubit gates.
Reversible logic is gaining significant consideration as the potential logic design style for implementation in modern nanotechnology and quantum computing with minimal impact on physical entropy. Recent advances in reversible logic allow schemes for computer architectures using improved quantum computer algorithms. We present a VHDL behavioral model for the design and simulation of the quantum interactions of qubits in theoretical reversible logic structures. Modeling IQ gates, as opposed to only Control-V gates or Toffoli gates, allows for a more robust model that more accurately reflects a theoretical reversible computing structure. This method is an extension to existing programming language and modeling method that allows for reversible logic structures to be designed, simulated, and verified. To the best of our knowledge, this is the first work in the behavioral model of integrated qubit gates.
Programmable reversible logic is emerging as a prospective logic design style for implementation in modern nanotechnology and quantum computing with minimal impact on circuit heat generation. Recent advances in reversible logic using and quantum computer algorithms allow for improved computer architecture and arithmetic logic unit designs. We present an optimization method for reversible logic synthesis based on the Integrated Qubit (IQ) library. This method works in conjunction with existing methods to further improve quantum cost and delay of a synthesized reversible logic circuit. This algorithm runs in O(N) time, and reduces the quantum cost of synthesized circuit by up to 45 percent. In addition, the process of replacing the gates in the synthesized circuits with IQ gates uses a locally optimal technique whose major benefits include reduction of cost as well as delay.
Significant debate exists in the literature with regards to the permissibility of feedback in reversible computing nanotechnologies. Feedback allows for reuse of logical subroutines, which is a desired functionality of any computational device. Determining whether loop back is allowed is paramount to assessing the robustness of reversible logic in any quantum design. In this paper, the fundamental discoveries in entropy and quantum mechanics that serve as the foundations for reversible logic are reviewed. The fundamentals for implementation of reversibility in computing are shown. Then, definitions are presented for a sequential reversible logic structure. A sequential reversible logic structure is proven to have an identical number of feedback-dependent inputs and feedback-producing outputs, and new metrics for measuring the probability of each output state are presented. Using these metrics, the reversibility of each clock cycle of such a device is verified. Therefore, we demonstrate that any reversible logic structure with feedback is physically reversible.
Reversible logic provides a foundation for nextgeneration computing systems, particularly in quantum and emerging nanotechnology-based architectures. Unlike conventional logic, reversible gates preserve information and support backward computation, making them crucial for designing quantum circuits. This paper introduces a reversible Arithmetic and Logic Unit (ALU) that performs eight fundamental operations-AND, OR, NOT, XOR, addition, subtraction, increment, and decrement-using Fredkin, Peres, TR, and modified Fredkin gates. A dedicated control unit manages operation selection, ensuring functional flexibility and circuit efficiency. The proposed design achieves significant improvements by minimizing ancilla inputs, quantum cost and garbage outputs, resulting in a total quantum cost of 71 and contains 16 reversible gates and 14 garbage outputs. The architecture was modeled and verified using Xilinx Vivado HLS and ISE 14.7, and implemented on the Nexys A7 (Artix-7) FPGA platform. Comparative analysis demonstrates better efficiency than existing reversible ALU designs, establishing the proposed circuit as a strong candidate for quantum computing and other advanced computing paradigms.
Quantum computing requires logic operations to be implemented as reversible transformations. Classical combinational circuits must therefore be redesigned using reversible gate structures when mapped to quantum systems. In this work, fundamental quantum digital circuits are implemented using CNOT and Toffoli gates using the Qiskit framework.In addition, an 8-qubit Quantum Random Number Generator (QRNG) is developed and analyzed. Hadamard operations are applied to an 8-qubit register to produce a uniform superposition over 256 states. Measurement in the computational basis generates an 8-bit result per execution. By repeating the circuit 16 independent times and concatenation of the outputs produce a 128-bit random sequence. The QRNG is evaluated using Dirac notation, density operator representation and entropy analysis to verify uniform probability distribution under ideal simulation conditions.Simulation results confirm the correct logical functionality of the reversible arithmetic circuits and demonstrate high entropy random sequence generation using quantum measurement. The presented framework provides a structured approach for implementing digital logic and randomness generation in Qiskit.
In the context of modern Very Large-Scale Integration (VLSI) technology, information loss has been a major concern. Logic gates (LG) such as AND, OR, and NOT have been found to result in information loss during their operations. To address this issue, reversible LGs have been created. The development and implementation of a high-speed, efficient full adder circuit employing reversible LGs like Feynman, Toffoli, and Peres gates. The design aims to improve computational and thermal efficiencies. The circuit refarding quantum costs (QC), garbage outputs, and ancillary inputs. The implemented the suggested design in Verilog and verified the entire adder's functionality and efficiency through simulations using the Xilinx Vivado and Xilinx ISE tools. The circuit has a quantum cost of 10 with two outputs of useless and one auxiliary input, according to the researchers, highlighting its opportunities for usage in quantum computing applications andlow-power (dec 84%), high-performance computing systems.
Reversible logic computation and optimization of reversible circuits help synthesize applications characterized by ultra‐low power consumption, including quantum information processing, the field of nanotechnology, semiconductor technology, the field of optics, and very‐large‐scale integration (VLSI), among others. Reversible logic design is a growing research subject that evaluates and applies resources in new advancements. This article provides an optimized, unique, resource‐constrained universal quantum reversible gate for nanoscale applications that perform all fundamental logic operations. Optimization and gate relocation have enhanced a published and proposed design. Quantum reversible circuits are optimized for cost and depth via template matching, gate fusion (merging) and commutation, gate decomposition, and gate elimination. These methods reduce circuit complexity and size significantly. A step‐by‐step optimization of the quantum reversible logic design is first presented. The novel quantum reversible gates MRQ1, MRQ2, and M‐BUS are implemented and verified on the IBM Qiskit platform. The proposed reversible gates’ design complexity is assessed using 13 standard Boolean expressions. Proposed quantum reversible gates demonstrate an improvement in performance, covering a range of 12.5%–72.7% over prior designs in gate count, depth, and quantum cost. Gate count improved most, impacting other parameters and demonstrating the design’s resource efficiency.