Diamonds are forever to change Amazon's quantum networks

De Beers, the renowned diamond company, is set to produce artificial diamonds for use in quantum computers that Amazon Web Services (AWS) is developing. Element Six, a De Beers subsidiary, will manufacture these artificial diamonds, which will be used by the AWS Center for Quantum Networking to develop quantum communications.

According to an AWS blog, quantum networks distribute "entanglement," which refers to the phenomenon that links the behaviour of particles together even when they are separated. This can significantly improve network security because it makes it impossible for hackers to read data from a network without being detected. Additionally, it allows data centres to synchronise classical computers and enables quantum computers to communicate quantum states, potentially allowing distributed quantum computing.

Quantum effects typically operate at a short range, which means quantum networking needs "quantum repeaters" to enable entanglement to be distributed over significant distances. Furthermore, quantum repeaters require operations to be carried out on single photons of light, which requires unprecedented levels of timing synchronisation.

AWS scientists believe that a rival qubit scheme based around colour defects in diamond, will be a better basis for quantum repeaters, which operate with photons - the basic unit of communication along fibre optic networks. The qubits, based on colour centres in diamonds, are called "defect qubits."

"Defects in solids are a wide class of qubits that consist of one or more atoms forming a defect inside an otherwise uniform, crystalline material," explained AWS authors, Dr. Bart Machielse and Dr. Daniel Riedel, and Dr. Daniel Twitchen from Element Six. "Depending on the type of atom and material used, the qubit is defined from the electronic or magnetic states of the defect atom(s)."

Diamonds consist of a rigid lattice of carbon atoms, but defects, containing impurity atoms, change the way they interact with light photons. This gives diamond gemstones their distinctive colours, but the photon effects can also enable quantum repeaters.

NV and SiV colour centres replace carbon atoms with nitrogen and silicon, respectively. These are colour centres, but their atoms also have a "spin memory," meaning that a magnetic field can align the "spin" of the defect, making it a quantum memory device, with a value of 1 or 0. Photons can flip the spin alignment, changing the value of the qubit.

Because they are in diamond, NV and SiV colour centres are more robust than other qubits and can potentially be built into deployable nanoscale networking devices. SiV defects, in particular, are not sensitive to background magnetic and electric fluctuations, making them particularly useful as they can be reliably written and read. The qubit also has a comparatively long "coherence time" of up to 10 milliseconds and a nuclear spin memory of more than a second.

Element Six has been working to create artificial diamonds with controlled defects, which have been used by Harvard and MIT scientists in quantum communication experiments, leading towards quantum repeaters. The company believes that such diamonds can be mass-produced in the future.

"Diamond’s optical and quantum properties make it uniquely promising for quantum networking and quantum communications applications," say the authors. "But lack of widespread access to different grades and morphologies of diamond has long been a challenge for the field. Element Six and AWS are working together to develop new technologies to make diamond a more flexible and accessible material – helping drive growth and progress for this technology."

Diamond's unique properties make it an ideal material for quantum networking and quantum communications applications. AWS's partnership with Element Six is critical in making the technology more accessible and flexible. The collaboration aims to develop innovative technologies that could enable the mass production of diamonds with various grades and morphologies.

The ability to produce artificial diamonds could make a significant contribution to quantum computing,

"Diamond's optical and quantum properties make it uniquely promising for quantum networking and quantum communications applications," wrote the authors of the AWS blog post. However, the lack of widespread access to different grades and morphologies of diamond has long been a challenge for the field. Element Six and AWS are working together to develop new technologies to make diamond a more flexible and accessible material, which will drive growth and progress for this technology.

The development of quantum networks could have far-reaching implications for the security of online communications. With the rise of quantum computing, traditional encryption methods could become vulnerable to attack. Quantum networks use entanglement, which ties the behaviour of particles together even when they are separated. This can improve the security of networks, making it impossible for hackers to read data from a network without being detected.

In addition to the security benefits, quantum networking could revolutionise data centres and computing. It enables classical computers to synchronise and communicate quantum states, potentially allowing distributed quantum computing. This technology could dramatically increase the speed and efficiency of data processing, allowing for a range of new applications, from complex simulations to drug discovery.

While most of the leading quantum computers are based around superconductors, the AWS Center for Quantum Networking is investigating a rival qubit scheme based around colour defects in diamond. The qubits, based on colour centres in diamond, are called "defect qubits," and they have unique properties that make them ideal for use in quantum networking.

"Defects in solids are a wide class of qubits which consist of one or more atoms forming a defect inside an otherwise uniform, crystalline material," explained the authors of the AWS blog post. "Depending on the type of atom and material used, the qubit is defined from the electronic or magnetic states of the defect atom(s)."

Diamonds consist of a rigid lattice of carbon atoms, but defects containing ‘impure’ atoms change the way they interact with light photons. This gives diamond gemstones their distinctive colours, but the photon effects can also enable quantum repeaters.

Nitrogen-Vacancy Center (NV) and Silicon-Vacancy Center (SiV) defects replace carbon atoms with nitrogen and silicon, respectively. These are colour centres, but their atoms also have a "spin memory" as a magnetic field can align the "spin" of the defect, making it a quantum memory device, with a value of 1 or 0. Photons can flip the spin alignment, changing the value of the qubit.

Because they are in diamond, NV and SiV colour centres are more robust than other qubits and can potentially be built into deployable nanoscale networking devices. SiV defects, in particular, are not sensitive to background magnetic and electric fluctuations, making them particularly useful as they can be reliably written and read. The qubit also has a comparatively long "coherence time" of up to 10 milliseconds, and a nuclear spin memory of more than a second.

Element Six has been working to create artificial diamonds with controlled defects, which have been used by Harvard and MIT scientists in quantum communication experiments, leading towards quantum repeaters. The company believes such diamonds can be mass-produced in future.