---
title: "Russian scientists perform three-qubit CCZ quantum operation directly with 99.39% accuracy for the first time"
description: "Russian scientists have performed a three-qubit CCZ operation directly with 99.39% accuracy for the first time, without breaking it down into a chain of two-qubit gates. The development could simplify quantum processor scaling."
date: 2026-11-10T13:16:16.303Z
lang: en
url: https://xab.info/en/posts/russian-scientists-three-qubit-ccz-quantum-operation
tags: [quantum-computing, three-qubit-gate, ccz, superconducting-qubits, fluxonium, transmon, russia]
author: "Alexander Buran"
publisher: "XAB.info"
---

# Russian scientists perform three-qubit CCZ quantum operation directly with 99.39% accuracy for the first time

![Superconducting quantum processor with qubits and gold wiring inside a dilution refrigerator](https://xab.info/media/2026/11/10/rossiiskie-uchenyie-trehkubitnaya-kvantovaya-operatsiya-ccz/rossiiskie-uchenyie-trehkubitnaya-kvantovaya-operatsiya-ccz-1.webp)

## Key Points

- Russian scientists performed a three-qubit CCZ operation directly for the first time, without a cascade of two-qubit gates
- The operation accuracy reached 99.39% on simpler hardware
- The device is built on three fluxonium qubits with a shared control transmon
- Control requires a single microwave pulse lasting 65 ns
- The architecture is suitable for integration into two-dimensional circuits and scaling

Modern quantum computers and algorithms predominantly rely on single- and two-qubit gates. To implement an operation involving three qubits, engineers have to sequentially execute eight two-qubit operations, which complicates algorithm structure and significantly increases error accumulation. Researchers from MISIS University, the Russian Quantum Center, the Institute of Nanotechnology of Microelectronics of the Russian Academy of Sciences, and MIPT have announced the execution of a complex operation involving three qubits simultaneously with record accuracy for this class of devices. It is important to clarify that this is not about creating a fully functional superconducting quantum processor, but rather about the ability to perform a complex three-qubit operation in a single step.

### Three fluxoniums and a shared control transmon

At the core of the device are three superconducting fluxonium qubits connected via a shared control element, a transmon. It is this element that allows targeting a specific combination of states of all three qubits simultaneously, executing the so-called CCZ (Controlled-Controlled-Z) operation. This operation changes the phase of one of eight possible qubit state combinations. Such gates are widely used in quantum algorithms, error correction systems necessary to improve computational reliability, and large integer factorization tasks, which potentially impacts cryptography and data security.

### A single pulse instead of a gate chain

"We experimentally implemented the three-qubit CCZ gate directly, rather than through a cascade of single- and two-qubit operations. At the same time, control remains as simple as for standard two-qubit gates: a single microwave pulse lasting 65 ns is sufficient, calibrated using traditional methods—Rabi and Ramsey oscillations—which track changes in qubit states under the influence of the microwave signal," said Grigory Mazhorin, a researcher at the Laboratory of Superconducting Quantum Technologies at NUST MISIS and the "Superconducting Qubits and Quantum Circuits" group at the RQC. This approach simplifies calibration and reduces the number of points where errors can occur.

### 99.39% accuracy on simpler hardware

The key advantage of the development lies in the ratio of accuracy to hardware complexity. Under the traditional approach, to achieve comparable accuracy for the final operation, individual two-qubit gates must operate with an accuracy of about 99.39% each? Wait, about 99.94% each, which is currently available only on a limited number of the most advanced and complex quantum computers. The Russian implementation, however, allows performing the same operation with 99.39% accuracy in a single step on simpler and less demanding hardware, lowering the barrier to entry for working with three-qubit gates.

### Scaling prospects

According to the developers themselves, the created architecture can serve as the basis for scaling superconducting quantum processors. The scientists note that the created module can be integrated into a two-dimensional circuit while maintaining mechanisms to suppress unwanted interactions between its elements. This paves the way for building larger quantum circuits without a proportional increase in control complexity and errors, which is one of the main barriers to practical quantum machines.

## Fact-Check & Sources

- [Российские учёные представили квантовый «процессор» с рекордной точностью в трёхкубитных операциях](https://3dnews.ru/1151097) - Primary source: team composition, architecture description (fluxoniums + transmon), CCZ operation, 99.39% accuracy, quote by G. Mazhorin, comparison with the traditional approach of 99.94% per gate.
- [Российские учёные создали трёхкубитный квантовый процессор с рекордной точностью](https://www.elec.ru/news/2026/11/10/rossijskie-uchyonye-vypolnili-tryokhkubitnuju-kvan.html) - Confirms 99.39% accuracy and the fundamental difference from the traditional approach with a chain of two-qubit gates.

## FAQ

### What exactly did Russian scientists do?

They experimentally implemented a three-qubit CCZ gate directly, performing the operation simultaneously on three qubits with a single microwave pulse rather than assembling it from a chain of single- and two-qubit gates.

### What is the accuracy of the performed operation?

The accuracy was 99.39%. For comparison, under the traditional approach for a comparable result, each two-qubit gate must operate with an accuracy of about 99.94%.

### Is this a full-fledged quantum processor?

No, strictly speaking, this is not about creating a superconducting quantum processor, but about the ability to perform a complex three-qubit operation with record accuracy on simpler equipment.

### What elements does the device consist of?

The core is based on three superconducting fluxonium qubits connected via a shared control element—a transmon—which allows influencing a combination of states of all three qubits.