Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers build transistor-like gate for quantum information processing -- with qudits

17.07.2019

Two-qudit gate on a photonic platform achieves massive entangled quantum state

Quantum information processing promises to be much faster and more secure than what today's supercomputers can achieve, but doesn't exist yet because its building blocks, qubits, are notoriously unstable.


A two-qudit gate, among the first of its kind, maximizes the entanglement of photons so that quantum information can be manipulated more predictably and reliably.

Credit: Purdue University image/Allison Rice

Purdue University researchers are among the first to build a gate - what could be a quantum version of a transistor, used in today's computers for processing information - with qudits. Whereas qubits can exist only in superpositions of 0 and 1 states, qudits exist in multiple states, such as 0 and 1 and 2. More states mean that more data can be encoded and processed.

The gate would not only be inherently more efficient than qubit gates, but also more stable because the researchers packed the qudits into photons, particles of light that aren't easily disturbed by their environment. The researchers' findings appear in npj Quantum Information.

The gate also creates one of the largest entangled states of quantum particles to date - in this case, photons. Entanglement is a quantum phenomenon that allows measurements on one particle to automatically affect measurements on another particle, bringing the ability to make communication between parties unbreakable or to teleport quantum information from one point to another, for example.

The more entanglement in the so-called Hilbert space - the realm where quantum information processing can take place - the better.

Previous photonic approaches were able to reach 18 qubits encoded in six entangled photons in the Hilbert space. Purdue researchers maximized entanglement with a gate using four qudits - the equivalent of 20 qubits - encoded in only two photons.

In quantum communication, less is more. "Photons are expensive in the quantum sense because they're hard to generate and control, so it's ideal to pack as much information as possible into each photon," said Poolad Imany, a postdoctoral researcher in Purdue's School of Electrical and Computer Engineering.

The team achieved more entanglement with fewer photons by encoding one qudit in the time domain and the other in the frequency domain of each of the two photons. They built a gate using the two qudits encoded in each photon, for a total of four qudits in 32 dimensions, or possibilities, of both time and frequency. The more dimensions, the more entanglement.

Starting from two photons entangled in the frequency domain and then operating the gate to entangle the time and frequency domains of each photon generates four fully-entangled qudits, which occupy a Hilbert space of 1,048,576 dimensions, or 32 to the fourth power.

Typically, gates built on photonic platforms to manipulate quantum information encoded in separate photons work only some of the time because photons naturally don't interact with each other very well, making it extremely difficult to manipulate the state of one photon based on the state of another.

By encoding quantum information in the time and frequency domains of photons, Purdue researchers made operating the quantum gate deterministic as opposed to probabilistic.

The team implemented the gate with a set of standard off-the-shelf equipment used daily in the optical communication industry.

"This gate allows us to manipulate information in a predictable and deterministic way, which means that it could perform the operations necessary for certain quantum information processing tasks," said Andrew Weiner, Purdue's Scifres Family Distinguished Professor of Electrical and Computer Engineering, whose lab specializes in ultrafast optics.

Next, the team wants to use the gate in quantum communications tasks such as high-dimensional quantum teleportation as well as for performing quantum algorithms in applications such as quantum machine learning or simulating molecules.

###

The work is funded in part by the National Science Foundation (Grant number 1839191-ECCS) and a Wigner Fellowship at Oak Ridge National Laboratory.

ABSTRACT

High-Dimensional Optical Quantum Logic in Large Operational Spaces

Poolad Imany,1,2 Jose A. Jaramillo-Villegas,1,2,3 Mohammed S. Alshaykh,1,2 Joseph M. Lukens,4 Ogaga D. Odele,1,2 Alexandria J. Moore,1,2 Daniel E. Leaird,1,2 Minghao Qi,1,5 Andrew M. Weiner1,2,5

1 School of Electrical and computer Engineering, Purdue University, West Lafayette, IN, USA

2 Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, IN, USA

3 Facultad de Ingenierías, Universidad Tecnológica de Pereira, Pereira, RIS, Colombia

4 Quantum Information Science Group, Oak Ridge National Laboratory, Oak Ridge, TN, USA

5 Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA

doi: 10.1038/s41534-019-0173-8

The probabilistic nature of single-photon sources and photon-photon interactions encourages encoding as much quantum information as possible in every photon for the purpose of photonic quantum information processing. Here, by encoding high-dimensional units of information (qudits) in time and frequency degrees of freedom using on chip sources, we report deterministic two-qudit gates in a single photon with fidelities exceeding 0.90 in the computational basis. Constructing a two-qudit modulo SUM gate, we generate and measure a single-photon state with non-separability between time and frequency qudits. We then employ this SUM operation on two frequency-bin entangled photons--each carrying two 32-dimensional qudits--to realize a four-party high-dimensional Greenberger-Horne-Zeilinger state, occupying a Hilbert space equivalent to that of 20 qubits. Although high-dimensional coding alone is ultimately not scalable for universal quantum computing, our design shows the potential of deterministic optical quantum operations in large encoding spaces for practical and compact quantum information processing protocols.

Media Contact

Kayla Wiles
wiles5@purdue.edu
765-494-2432

 @PurdueUnivNews

http://www.purdue.edu/ 

Kayla Wiles | EurekAlert!
Further information:
https://www.purdue.edu/newsroom/releases/2019/Q3/researchers-build-transistor-like-gate-for-quantum-information-processing-with-qudits.html
http://dx.doi.org/10.1038/s41534-019-0173-8

More articles from Information Technology:

nachricht Research alliance: TRUMPF and Fraunhofer IPA ramping up artificial intelligence for industrial use
06.08.2020 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Novel approach improves graphene-based supercapacitors
03.08.2020 | University of Technology Sydney

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: ScanCut project completed: laser cutting enables more intricate plug connector designs

Scientists at the Fraunhofer Institute for Laser Technology ILT have come up with a striking new addition to contact stamping technologies in the ERDF research project ScanCut. In collaboration with industry partners from North Rhine-Westphalia, the Aachen-based team of researchers developed a hybrid manufacturing process for the laser cutting of thin-walled metal strips. This new process makes it possible to fabricate even the tiniest details of contact parts in an eco-friendly, high-precision and efficient manner.

Plug connectors are tiny and, at first glance, unremarkable – yet modern vehicles would be unable to function without them. Several thousand plug connectors...

Im Focus: New Strategy Against Osteoporosis

An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.

Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...

Im Focus: AI & single-cell genomics

New software predicts cell fate

Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...

Im Focus: TU Graz Researchers synthesize nanoparticles tailored for special applications

“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.

Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...

Im Focus: Tailored light inspired by nature

An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.

Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“Conference on Laser Polishing – LaP 2020”: The final touches for surfaces

23.07.2020 | Event News

Conference radar for cybersecurity

21.07.2020 | Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

 
Latest News

Rare Earth Elements in Norwegian Fjords?

06.08.2020 | Earth Sciences

Anode material for safe batteries with a long cycle life

06.08.2020 | Power and Electrical Engineering

Turning carbon dioxide into liquid fuel

06.08.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>