Keywords: digital quantum coprocessor, digital qubit, quantum Fourier transform.


It is shown that true quantum computers are analog and probabilistic computers and, in fact,
they play the role of coprocessors in relation to classical computers. A digital quantum coprocessor consists of digital qubits. Each digital qubit is a finite state machine, the state changes of which is described in the same way as the state changes of an analog qubit. A digital qubit is a chain of digital quantum gates. Each digital quantum gate is digital unit, the state changes of which is described in the same way as the state changes of an analog quantum gate. The main difference between digital qubit and digital quantum gate from analog ones is the presence of memory (more precisely, the possibility of its introduction into their circuit) and its use for organizing calculations. A digital qubit without feedbacks - a digital quantum gate that can be controlled using a classic computer, is a single step of a pipeline with a measurement unit (comparator), a pipeline register and a pipeline trigger at the output. The quantum Fourier transform (QFT) is part of many quantum algorithms, in particular the Shor's
factorization algorithm. The structures of digital quantum gates, digital qubits, and a digital quantum
coprocessor capable of performing the QFT are presented. The results of the QFT of a multi-qubit digital quantum coprocessor implemented on one FPGA are presented. For this, a IP core generator of multi-qubit quantum coprocessors was created, cores work was simulated. Models were implemented in FPGAs and their time and hardware characteristics were determined. The execution time of one quantum Fourier transform does not depend on the number of qubits in the digital quantum coprocessor and is commensurate with the time of change of the electron spin. The hardware complexity linearly depends on the number of qubits. With an increase in the number of qubits, the rate of true results of QFT decreases, at 64 qubits it is 1.5%, the decrease is nonlinear

Author Biography

Валерий Сергеевич Глухов, National University "Lviv Polytechnic"

Doctor of Technical Sciences, Professor, Professor Department of Electronic Computing Machines

How to Cite
Глухов, В. (2019). FPGA-BASED K-QUBIT DIGITAL QUANTUM COPROCESSOR. Electrotechnic and Computer Systems, (31(107), 104-116. https://doi.org/10.15276/eltecs.31.107.2019.10
Computer Systems, Networks and their Components