Generating remote entanglement via disentangling operations

Shared entanglement between spatially separated systems is an essential resource for quantum information processing including long-distance quantum cryptography and teleportation. While purification protocols for mixed distributed entangled quantum states exist, it is not clear how to optimally distribute entanglement to remote locations. Here, we describe a deterministic protocol for generating a maximally entangled state between remote locations that only uses local operations on qubits, and requires no classical communication between the separated parties. The procedure may provide protection from decoherence before the entanglement is "activated," and could be useful for quantum key distribution.Comment: 6 pages, 3 figure

Electricity system based on 100% renewable energy for India and SAARC

<div><p>The developing region of SAARC (South Asian Association for Regional Cooperation) is home to a large number of people living below the poverty line. In future, providing affordable, universally accessible, reliable, low to zero carbon electricity in this region will be the main aim. A cost optimal 100% renewable energy system is simulated for SAARC for the year 2030 on an hourly resolved basis. The region was divided into 16 sub-regions and three different scenarios were set up based on the level of high voltage direct current (HVDC) grid connections. The results obtained for a total system levelised cost of electricity (LCOE) showed a decrease from 71.6 €/MWh in a decentralized to 67.2 €/MWh for a centralized grid connected scenario. An additional scenario was simulated to show the benefits of integrating industrial gas production and seawater reverse osmosis desalination demand, and showed the system cost decreased by 5% and total electricity generation decreased by 1%. The results show that a 100% renewable energy system could be a reality in the SAARC region with the cost assumptions used in this research and it may be more cost competitive than nuclear and fossil carbon capture and storage (CCS) alternatives. One of the limitations of this study is the cost of land for installation of renewables which is not included in the LCOE calculations, but regarded as a minor contribution.</p></div

Yearly profile for PV single-axis tracking (left) and wind onshore (right).

<p>Yearly profile for PV single-axis tracking (left) and wind onshore (right).</p

Model flow diagram with the input data, system model optimization and output data.

<p>Model flow diagram with the input data, system model optimization and output data.</p

Financial results for the four scenarios applied for the SAARC region.

<p>Financial results for the four scenarios applied for the SAARC region.</p

Sub-regional annual import and export of electricity for area-wide (left) and integrated scenario (right).

<p>Sub-regional annual import and export of electricity for area-wide (left) and integrated scenario (right).</p

Key findings of different scenario studies for SAARC.

<p>Key findings of different scenario studies for SAARC.</p

Energy flow of the system in the integrated scenario for the year 2030.

<p>Energy flow of the system in the integrated scenario for the year 2030.</p

Aggregated load curve (left) and load curve with prosumers influence (right) for the SAARC region for the year 2030.

<p>Aggregated load curve (left) and load curve with prosumers influence (right) for the SAARC region for the year 2030.</p

Installed RE technologies and storage capacities for the four scenarios for SAARC region.

<p>Installed RE technologies and storage capacities for the four scenarios for SAARC region.</p