Nav: Home

Quantum race accelerates development of silicon quantum chip

January 25, 2018

The worldwide race to create more, better and reliable quantum processors is progressing fast, as a team of TU Delft scientists led by Professor Vandersypen has realised yet again. In a neck-and-neck race with their competitors, they showed that quantum information of an electron spin can be transported to a photon, in a silicon quantum chip. This is important in order to connect quantum bits across the chip and allowing to scale up to large numbers of qubits. Their work was published today in the journal Science.

The quantum computer of the future will be able to carry out computations far beyond the capacity of today's computers. Quantum superpositions and entanglement of quantum bits (qubits) make it possible to perform parallel computations. Scientists and companies worldwide are engaged in creating increasingly better quantum chips with more and more quantum bits. QuTech in Delft is working hard on several types of quantum chips.

Familiar material

The core of the quantum chips is made of silicon. "This is a material that we are very familiar with," explains Professor Lieven Vandersypen of QuTech and the Kavli Institute of Nanoscience Delft, "Silicon is widely used in transistors and so can be found in all electronic devices." But silicon is also a very promising material for quantum technology. PhD candidate Guoji Zheng: "We can use electrical fields to capture single electrons in silicon for use as quantum bits (qubits). This is an attractive material as it ensures the information in the qubit can be stored for a long time."

Large systems

Making useful computations requires large numbers of qubits and it is this upscaling to large numbers that is providing a challenge worldwide. "To use a lot of qubits at the same time, they need to be connected to each other; there needs to be good communication", explains researcher Nodar Samkharadze. At present the electrons that are captured as qubits in silicon can only make direct contact with their immediate neighbours. Nodar: "That makes it tricky to scale up to large numbers of qubits."

Neck-and-neck race

Other quantum systems use photons for long-distance interactions. For years, this was also a major goal for silicon. Only in recent years have various scientists made progress on this. The Delft scientists have now shown that a single electron spin and a single photon can be coupled on a silicon chip. This coupling makes it possible in principle to transfer quantum information between a spin and a photon. Guoji Zheng: "This is important to connect distant quantum bits on a silicon chip, thereby paving the way to upscaling quantum bits on silicon chips."

On to the next step

Vandersypen is proud of his team: "My team achieved this result in a relatively short time and under great pressure from worldwide competition." It is a true Delft breakthrough: "The substrate is made in Delft, the chip created in the Delft cleanrooms, and all measurements carried out at QuTech," adds Nodar Samkharadze. The scientists are now working hard on the next steps. Vandersypen: "The goal now is to transfer the information via a photon from on electron spin to another."
This research was funded by an ERC Synergy Grant, NWO via the Nanofront Program and Intel.

In a separate study published in the same issue of Science today, other researchers from the Kavli institute of Nanoscience at TU Delft also found a way to transfer spin information to photons. Read the press release about this related research here.

Delft University of Technology

Related Quantum Information Articles:

A new quantum data classification protocol brings us nearer to a future 'quantum internet'
A new protocol created by researchers at the Universitat Autònoma de Barcelona sorts and classifies quantum data by the state in which they were prepared, with more efficiency than the equivalent classical algorithm.
Extracting hidden quantum information from a light source
Researchers report on a technique to extract the quantum information hidden in an image that carries both classical and quantum information.
Ultrafast particle interactions could help make quantum information devices feasible
Research presents the detection of energy transfer from excited electrons to the crystal lattice on the femtosecond timescale.
Shaping nanoparticles for improved quantum information technology
Argonne researchers find that semiconductor nanoparticles in the shape of rings have attractive properties for quantum networking and computation.
Next-generation single-photon source for quantum information science
University of Illinois Physics Professor Paul Kwiat and his former postdoctoral researcher Fumihiro Kaneda (now at Tohoku University) have built what Kwiat believes is 'the world's most efficient single-photon source.' And they are still improving it.
'Poor man's qubit' can solve quantum problems without going quantum
Researchers have built and demonstrated the first hardware for a probabilistic computer, a possible way to bridge the gap between classical and quantum computing.
Quantum computers to clarify the connection between the quantum and classical worlds
Los Alamos National Laboratory scientists have developed a new quantum computing algorithm that offers a clearer understanding of the quantum-to-classical transition, which could help model systems on the cusp of quantum and classical worlds, such as biological proteins, and also resolve questions about how quantum mechanics applies to large-scale objects.
Imaging of exotic quantum particles as building blocks for quantum computing
Researchers have imaged an exotic quantum particle -- called a Majorana fermion -- that can be used as a building block for future qubits and eventually the realization of quantum computers.
Quantum interference in service of information technology
Scientists from the Faculty of Physics, University of Warsaw, in collaboration with the University of Oxford and the NIST agency, have shown that quantum interference enables processing of large sets of data faster and more accurately than with standard methods.
Researchers build transistor-like gate for quantum information processing -- with qudits
Purdue University researchers are among the first to build what could be a quantum version of a transistor -- with qudits.
More Quantum Information News and Quantum Information Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab