Why Quantum Computers Might Not Break Cryptography

A new paper claims that a common digital security system could be tweaked to withstand attacks even from a powerful quantum computer. …

Read More...

Comments Off on Why Quantum Computers Might Not Break Cryptography

Physics may bring faster solutions for tough computational problems

Researchers have used an elegant method based on statistical mechanics — called the vertex model — to create more efficient algorithms to solve complex problems more quickly. The research could solve problems in machine learning, circuit optimization and other major computational challenges.

Read More...

Comments Off on Physics may bring faster solutions for tough computational problems

Electrostatic design of materials: A fundamentally new approach

Researchers have mapped out a radically new approach for designing optical and electronic properties of materials.

Read More...

Comments Off on Electrostatic design of materials: A fundamentally new approach

Can Darwinian Evolution Explain Lamarckism?

Answering three questions can help reveal how the “inheritance of acquired characteristic” fits into modern evolutionary theory. …

Read More...

Comments Off on Can Darwinian Evolution Explain Lamarckism?

Fundamental limitation on quantum broadcast networks

The ability to distribute entanglement over complex quantum networks is an important step towards a quantum internet. Recently, there has been significant theoretical effort, mainly focusing on the distribution of bipartite entanglement via a simple quantum network composed only of bipartite quantum channels. There are, however, a number of quantum information processing protocols based on multipartite rather than bipartite entanglement. Whereas multipartite entanglement can be distributed by means of a network of such bipartite channels, a more natural way is to use a more general network, that is, a quantum broadcast network including quantum broadcast channels. In this work, we present a general framework for deriving upper bounds on the rates at which GHZ states or multipartite private states can be distributed among a number of different parties over an arbitrary quantum broadcast network. Our upper bounds are written in terms of the multipartite squashed entanglement, cor… …

Read More...

Comments Off on Fundamental limitation on quantum broadcast networks

Experimentally exploring compressed sensing quantum tomography

In the light of the progress in quantum technologies, the task of verifying the correct functioning of processes and obtaining accurate tomographic information about quantum states becomes increasingly important. Compressed sensing, a machinery derived from the theory of signal processing, has emerged as a feasible tool to perform robust and significantly more resource-economical quantum state tomography for intermediate-sized quantum systems. In this work, we provide a comprehensive analysis of compressed sensing tomography in the regime in which tomographically complete data is available with reliable statistics from experimental observations of a multi-mode photonic architecture. Due to the fact that the data is known with high statistical significance, we are in a position to systematically explore the quality of reconstruction depending on the number of employed measurement settings, randomly selected from the complete set of data, and on different model assumptions. We pre… …

Read More...

Comments Off on Experimentally exploring compressed sensing quantum tomography

Stretchable hologram can switch between multiple images

The possibility of sending and receiving holographic messages has long tantalized sci-fi fans. Although we’re not there yet, scientists have now created holograms that can change from one image to another as the materials used to generate them are stretched.

Read More...

Comments Off on Stretchable hologram can switch between multiple images

Exploring the conversion of heat to electricity in single molecules

Researchers have investigated the influence of the geometry of single-molecule devices on their ability to produce electricity from heat. They fabricated devices consisting of a single molecule bridging gold electrodes and measured device electrical conductance and thermovoltage simultaneously. The devices with thiol-gold contacts displayed the highest thermovoltage when the gold-thiol bond was stretched, revealing that the thermoelectric performance of single-molecule devices can be modulated through geometry control.

Read More...

Comments Off on Exploring the conversion of heat to electricity in single molecules