New ultra-low loss waveguide platform published in Optics Express

A new integrated photonics platform has been developed by the Quantum Photonics Laboratory at RMIT.

This platform enables great advancements in both academic research and in commercial telecommunications.

The research team has developed a new fabrication method to create highly compact photonic circuits in lithium niobate, one of the most promising materials platforms for integrated photonics.

Lithium niobate, the central platform for telecommunication technology, promises fast reconfigurable circuits and nonlinear optical signal processing. To date, however, lithium niobate devices have been limited by component size.

The new platform developed in the Quantum Photonics Lab allows highly compact circuits while achieving very low propagation loss; a key requirement for any integrated photonic technology.

These results have recently been published in Optics Express and have already been cited several times in a matter of weeks.

Link to the article

Quantum enhanced transmission over an amplitude damping channel published in Physical Review A

A new protocol demonstrating quantum enhanced robustness to noise has been implemented by the Quantum Photonics Lab

The novel scheme requires only one additional bit of data and entanglement to dramatically increase the data recovery probability.

When a single data bit is transmitted, the success probability is experimentally enhanced by over 20%.

Furthermore, when a two-bit message is transmitted, the enhancement is over 50% compared to optimal clasical protocol.

These key results have recently been published in Physical Review A.

Link to the article

QPLab member awarded RMIT Research prize

Congratulations to Robert Chapman for being awarded the prestigious 2017 Vice-Chancellor’s Prize for Research Impact.
The RMIT Research Awards recognise and celebrate the research achievements of our staff and Higher Degree by Research (HDR) candidates.

New genetic algorithm to map the ‘edge of reality’ published in Physical Review A

Australian and German researchers have collaborated to develop a genetic algorithm to confirm the rejection of classical notions of causality.

RMIT’s Dr Alberto Peruzzo said: “Bell’s theorem excludes classical concepts of causality and is now a cornerstone of modern physics.

“But despite the fundamental importance of this theorem, only recently was the first ‘loophole-free’ experiment reported which convincingly verified that we must reject classical notions of causality.

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QPLab Secures ARC Funding for Centre of Excellence in 2017

The ARC’s seven-year budget will support nine new Centres of Excellence, which involve significant collaboration between universities, publicly funded research organisations, other research bodies, governments and businesses.The aim, according to the ARC, is to undertake highly innovative and potentially transformational research with the aim of achieving international standing and a significant advancement of capabilities and knowledge.

RMIT researchers are chief investigators, leading collaboration across multiple universities, in three successful bids. Dr Alberto Peruzzo (School of Engineering) and Dr Nicolas Menicucci (School of Science) have secured funds for a new round of the Centre for Quantum Computation and Communication Technology. This centre will receive $33.7 million to implement quantum processors able to run error corrected algorithms and transfer information across networks with absolute security. The new technology is expected to provide a strategic advantage in a world where information security is of paramount importance.

Link to RMIT press release

Self-guided quantum tomography published in Physical Review Letters

In this paper we report on the experimental demonstration of self-guided quantum tomography—a first of its kind iterative method to characterize quantum systems—and show its superior performance and robustness over standard quantum tomography in several photonic one- and two-qubit experiments. Standard quantum tomography requires storing and post-processing data from an exponentially large number of measurements, making this technique inapplicable for quantum states being prepared today. Moreover, it lacks robustness against inevitable statistical noise and measurement errors.

By iteratively learning the quantum state through a stochastic optimization algorithm, self-guided quantum tomography is far more resource efficient—thus can be applied to larger systems—and achieves higher accuracy thanks to its robustness against statistical noise and measurement errors.

Self-guided quantum tomography will likely be soon necessary in quantum experiments where standard quantum tomography is already unfeasible. Applications of the algorithm outside quantum tomography include state preparation and quantum device control. As automation will be critical for future quantum technologies, our demonstration takes an important step towards practical realization of autonomous learning.

Link to the article

Quantum state transfer published in Nature Communications

In an international collaboration between the Quantum Photonics Laboratory at RMIT, the Politecnico di Milano and the South University of Science and Technology of China, we have demonstrated, for the first time the perfect state transfer of an entangled quantum bit (qubit) on an integrated photonic device.

The ability of information transfer is at the heart of every information processing system, from global satellite communication to biological neural networks. Likewise, quantum technologies require high fidelity routing of quantum information between different locations of a quantum processor and quantum communication nodes. Due to the long-standing challenge of preserving extremely fragile quantum correlation, despite numerous theoretical proposals, to date, the perfect state transfer protocol has not been experimentally realized on quantum bits of information. In this work we report the first demonstration of perfect state transfer protocol.

Using the state-of-the-art three-dimensional direct-write waveguide technology, we fabricated an integrated waveguide array with a specific design, showing the capability of high fidelity transfer of quantum states.
We anticipate that our realisation of the perfect state transfer protocol has direct applications in many areas, including quantum transport, quantum simulation, entanglement preparation and distribution, and qubit interconnection for quantum computation. These applications may induce fundamental changes in the way we design the infrastructure of the next-generation quantum information processing devices, saving more space and allowing more automation.

Link to the article

Welcome to the new members of QPL

Today Dr Andreas Boes joins QPL as a postdoctoral fellow and Akib Karim and Inna Krasnokutska start their PhD on quantum photonics.

Welcome everyone!