Quantum computing is expected to help researchers solve some of the most complex problems in the future, but before that, the Toshiba research team completed 600 km (373 miles) of optical fiber quantum communication experiments.Reports that traditional computers only use single-bit encoding, such as “0” or “1”. But in quantum computers, quits allow the existence of superposition states, which greatly expands the computing possibilities, i.e. they can solve problems beyond the capabilities of traditional computers.

Data Map (Posted by: Toshiba Official Website)

For example, last year, a domestic nine-chapter quantum computer completed a calculation in 200 seconds, which would take 2.5 billion years for a typical supercomputer.

However, the biggest challenge of quantum computing is that quits are very sensitive to environmental interference. Even very small temperature fluctuations or fluctuations can affect the validity of the data, which means that long-distance quantum data transfer is also very difficult.

Research Figure-1: Experimental tool

The good news is that in a recent article published in the journal Nature Photonics, Toshiba’s research team has unveiled a new distance record they have set for quantum communication via optical fiber.

The key to the success of the experiment lies in the new technology it has developed called “dual band stability”. Based on the quit, it will send two optical reference signals.

Research Figure-2: Dual-frequency stability scheme

These signals are encoded with a phase delay of weak light pulses, where the wavelength of the first reference signal is designed to withstand environmental disturbances. The operating wavelength of the second reference signal is equal to the quilt itself to accurately control the phase of the light.

Based on this, the Toshiba team was able to retain quantum signals within tens of thousands of nanometers, instead allowing them to transmit optical fiber data over 600 kilometers – six times the previous record.

Research Figure-3: Critical rate simulation and results

Although it is not the longest quantum information transmission record ever achieved, the satellite transmission still tops the list, taking advantage of 1,200 km (746 mi), and quantum internet still needs to be integrated with satellite / light networks.

The team pointed out that this technology would be the first to be used for quantum key distribution (QQD for short). Thanks to the strange laws of quantum physics, this encryption technology can make changes to behavior when monitored by a third party, allowing users to be more cautious and vulnerable to potential hackers.

Research Figure-4: Quits Extracted Binary Point Bitmap

Andrew Shields, head of Toshiba’s Europe’s quantum technology division, said: “In recent years, quantum key distribution has been used to protect metropolitan area networks.”

This latest development expands the scope of the latest quantum links that enable broadcasts to be achieved in cities, countries and even continents without the use of trusted intermediate nodes.

By implementing this with the Satellite QKD program, the new program will enable us to build a secure network based on quantum communication globally.

Details of this research were recently published in “Nature PhotonicsIn the journal, the original title was “Quantum Communications Like a 600km Repeater with Dual-Band Stability”.