News / Highlights / Colloquium

EPJ QT Highlight - How does Earth’s spacetime deformation affect quantum communications?

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Credit: CQT, National University of Singapore

Jan Kohlrus investigates relativitic effects to consider when setting up quantum communication systems.

The interplay and overlap between relativity and quantum theory are among the most complex and challenging open problems of modern theoretical physics. This grey area has been extensively studied on the theoretical side, sometimes following very speculative and exotic directions, while very few experiments have been proposed in a way that rigorously incorporates relativity and quantum features.

The purpose of our work is to propose feasible experiments that involve quantum fields in a relativistic framework. In our recent article in EPJ Quantum Technology, we study how observers that undergo different motion, and experience different strengths of the gravitational field, measure pulses of light that propagate from one user to another. In particular, we look at quantum communication schemes between Earth and satellite links, as well as between two satellites.

Continue reading Jan’s post here.

EPJ QT Highlight - Quantum security from small satellites

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Credit: CQT, National University of Singapore

Shoebox sized satellites could be the key to fast-track development of space quantum communication, writes author Daniel Oi in a contribution to the SpringerOpen blog.

Quantum computing threatens the security of public key cryptosystems that secure the internet. But what quantum takes away, it can also give back. The technique of quantum key distribution (QKD) promises codes that are guaranteed by physics to be, in principle, unbreakable.

In EPJ Quantum Technology, we propose a CubeSat Quantum Communications Mission (CQuCoM) with a vision towards a globe-spanning constellation of QKD satellites. We are an international consortium of six research entities and one company across six countries.

Continue reading the blog post here.

EPJ Quantum Technology Review - Macroscopic Quantum Resonators (MAQRO): 2015 update

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Do the laws of quantum physics still hold for macroscopic objects - this is at the heart of Schrödinger’s cat paradox - or do gravitation or yet unknown effects set a limit for massive particles? What is the fundamental relation between quantum physics and gravity? Ground-based experiments addressing these questions may soon face limitations due to limited free-fall times and the quality of vacuum and microgravity. The proposed mission Macroscopic Quantum Resonators (MAQRO) may overcome these limitations and allow researchers to address such fundamental questions. MAQRO harnesses recent developments in quantum optomechanics, high-mass matter-wave interferometry as well as state-of-the-art space technology to push macroscopic quantum experiments towards their ultimate performance limits and to open new horizons for applying quantum technology in space. The main scientific goal is to probe the vastly unexplored ‘quantum-classical’ transition for increasingly massive objects, testing the predictions of quantum theory for objects in a size and mass regime unachievable in ground-based experiments. The hardware will largely be based on available space technology.

In this review article, the authors present the MAQRO proposal submitted in response to the ESA's 4th Cosmic Vision call for a medium-sized mission (M4) with a possible launch in 2025, and review the progress with respect to the original MAQRO proposal made in 2010. In particular, the updated proposal overcomes several critical issues of the original proposal by relying on established experimental techniques from high-mass matter-wave interferometry and by introducing novel ideas for particle loading and manipulation. Moreover, the mission design was improved to better fulfil the stringent environmental requirements for macroscopic quantum experiments.

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EPJ Quantum Technology Highlight - Gold-diamond nanodevice for hyperlocalised cancer therapy

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Colocalisation studies with confocal fluorescence microscopy and acidotropic probes show particles trapped in the lysosomes of the living HeLa cells

Gold nanorods can be used as remote controlled nanoheaters delivering the right amount of thermal treatment to cancer cells, thanks to diamond nanocrystals used as temperature sensors

Precise targeting biological molecules, such as cancer cells, for treatment is a challenge, due to their sheer size. Now ,Taiwanese scientists have proposed an advanced solution, based on a novel combination of previously used techniques, which can potentially be applied to thermal cancer therapy. Pei-Chang Tsai from the Institute of Atomic and Molecular Sciences, at the Academia Sinica, Taipei, and colleagues just published in EPJ QT an improved sensing technique for nanometre-scale heating and temperature sensing. Using a chemical method to attach gold nanorods to the surface of a diamond nanocrystal, the authors have invented a new biocompatible nanodevice. It is capable of delivering extremely localised heating from a near-infrared laser aimed at the gold nanorods, while accurately sensing temperature with the nanocrystals.

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EPJ Quantum Technology Highlight - Quantum simulators explained

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A quantum simulator can then loosely be considered to be a simulator for the system of interest. © Johnson et al.

Everything you ever wanted to know about quantum simulators has been summed up in a new review from EPJ Quantum Technology

As part of a new Thematic Series on Quantum Simulations, the open access journal EPJ Quantum Technology has just published an overview of what a quantum simulator is, namely: a device that actively uses quantum effects to answer questions on model systems. This review, published by Tomi Johnson and colleagues from the Centre for Quantum Technologies in Singapore and the University of Oxford, UK, outlines various approaches used in quantum simulators.

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EPJ Quantum Technology – A new Open-Access Journal is launched

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The publishers are pleased to announce the launch of a new open-access journal in the EPJ series – EPJ Quantum Technology. The journal has just gone live, with three research papers already available.

Driven by advances in technology and experimental capability, the last decade has seen the emergence of quantum technology: a new praxis for controlling the quantum world. It is now possible to engineer complex, multi-component systems that merge the once distinct fields of quantum optics and condensed matter physics.

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Editor-in-Chief
G. Milburn
ISSN: 2196-0763 (Electronic Edition)

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