University of Innsbruck Researchers Fully Involve Two Qudits

Insider Summary

• A team of researchers from the University of Innsbruck demonstrated a way to efficiently create high-dimensional system entanglement to enable more robust computations.
• The researchers completely engaged two qudits, or quantum digits, each encoded by up to 5 individual Calcium ion states.
• According to the researchers, this gives physicists new tools to go beyond processing binary information, which could result in faster and more powerful quantum computers.

PRESS RELEASE — It’s only recently that quantum computers have begun to work with much more than the zeros and numbers we know from classical computers. Now a team at the University of Innsbruck, Austria, demonstrated a way to efficiently create high-dimensional system entanglement to enable more robust computations.

In the computing world, we usually think of information as being stored as ones and zeros – also known as binary encoding. However, in our daily life we ​​use ten digits to represent all possible numbers. In binary the number 9 is written as 1001 for example, requiring three additional digits to represent the same.

Today’s quantum computers grew out of this binary paradigm, but in reality physical systems that encode quantum bits (qubits) often also have the potential to encode quantum digits (qudits), as recently demonstrated by a team led by Martin Ringbauer in the Department of Experimental Physics at the University of Innsbruck. According to experimental physicist Pavel Hrmo at ETH Zurich: “The challenge for qudit-based quantum computers is to create efficient entanglement between high-dimensional information carriers.”

In a study published in journal of Nature Communications a team at the University of Innsbruck now reports how two qudits can be completely entangled with each other with unprecedented performance, paving the way for more efficient and powerful quantum computers.

Think like a quantum computer

The number 9 example shows that, while humans can calculate 9 x 9 = 81 in one step, a classical computer (or calculator) has to take 1001 x 1001 and perform many steps of binary multiplication behind the scenes before it can be calculated. able to display 81 on the screen. Classically, we are capable of this, but in a quantum world where computation is inherently sensitive to external noise and disturbances, we need to reduce the number of operations required to make the most of available quantum computers.

Crucial to any computation on a quantum computer is quantum entanglement. Entanglement is one of the unique quantum features that underpins the quantum potential to outperform classical computers in certain tasks. However, exploiting this potential requires the generation of strong and accurate high-dimensional attachments.

Natural language of quantum systems

Researchers at the University of Innsbruck are now able to fully engage two qudits, each of which encodes up to 5 individual Calcium ion states. This gives theoretical and experimental physicists new tools to move beyond processing binary information, which could result in faster and more powerful quantum computers.

Martin Ringbauer explains: “Quantum systems have many available states waiting to be used for quantum computing, rather than limiting them to work with qubits.”

Many of today’s most challenging problems, in fields as diverse as chemistry, physics, or optimization, can benefit from this more natural language of quantum computing.

This research was supported financially by, among others, the Austrian Science Fund FWF, Austrian Research Promotion Agency FFG, European Research Council ERC, European Union and Federation of Austrian Industries Tyrol.