#quantumapplications

[govindhtech]

Medium Earth Orbit Satellites For Global Quantum Internet

Recent studies have highlighted how crucial Medium Earth Orbit (MEO) satellites are to the ambitious goal of a global quantum internet with capabilities beyond regular telecommunications. These satellites will disperse entanglement over large distances, bridging geographic gaps where terrestrial fibre optic networks are limited. Quantum network integration into urban fibre infrastructure, like Berlin's BearlinQ, supports this global effort. These activities lay the groundwork for a truly interconnected quantum future.

Medium Earth Orbit Strategic Advantage

Long-distance quantum network setup has been problematic. Because optical fibres lose signal, complex quantum repeaters are needed to improve entangled photon range. Satellite-based systems have a larger reach but are limited by logistical issues, diffraction losses, and atmospheric interference.

Northwestern University, the University of Arizona, and its partners created a hybrid network protocol that benefits from fibre optic and satellite technologies to tackle these challenges. Medium Earth Orbit (MEO) satellites, strategically placed 10,000 kilometres above Earth, are at the heart of this continental-scale system.

This MEO altitude has many advantages:

It links widely distant ground stations better than Low Earth Orbit (LEO) satellites due to its wider coverage area. Minimised Photon Loss: Most notably, it minimises photon loss significantly compared to GEO satellites. This method maintains sensitive quantum states while providing extensive spatial coverage.

This hybrid system relies on MEO satellites to bridge large distances where fibre optic cable is impractical. For shorter links, the network uses optical fibres with high-fidelity entanglement distribution. This integrated technique improves fidelity and performance over fibre- or satellite-based systems. Using the contiguous US as an example, the scientists showed that this hybrid technique is more stable and scalable than both previous ways for diffusing entanglement over broad areas.

The MEO-integrated network will enhance quantum repeater technology. Quantum information is stored and retransmitted by these repeaters to overcome optical fibre signal loss. Photon repeaters enable entanglement switching, which extends entanglement distribution across great distances, and trapped ions serve as quantum memory.

The researchers painstakingly analysed air extinction and diffraction for satellite communications and signal loss in fibre optic networks to ensure their method is realistic. Distillation was added to enhance efficiency by purifying entangled states, removing noise, and strengthening entanglement for reliable long-distance communication. This careful component balance makes a quantum internet that can enable secure and effective cross-continental communication viable.

BearlinQ: Metropolitan Quantum Network Mastery

Integrating quantum capabilities into urban infrastructure is key to the quantum internet, which complements MEO satellites' global reach. Deutsche Telekom AG and Qunnect Inc. showcased the BearlinQ project, a scalable, real-world quantum networking testbed in Deutsche Telekom's Berlin metropolitan fibres. This project proves hybrid quantum-classical networks can work in cities.

BearlinQ's ability to support quantum communications and bidirectional classical C-band traffic on the same fibres without new connections or infrastructure changes is a major development. This is done with predicted wavelength separation:

The O-band (1324 nm) transmits quantum information. The O-band for low-noise quantum channels decreases spontaneous Raman scattering, a key source of noise, by ensuring that most Raman noise falls outside the quantum detection window. Classical data is mostly sent in the C-band, which has great channel density. Read about quantum entanglement entropy and challenges.

BearlinQ disperses polarization-entangled photon pairs via dynamically chosen fibre cables from 10 meters to 82 kilometres. Polarisation encoding is sensitive to ambient birefringence fluctuations despite being compatible with quantum memories. BearlinQ employs Automatic Polarisation Compensator (APC) technology to monitor and compensate for polarisation drifts to maintain a stable and scattered polarisation reference across all nodes. By time-multiplexing across the same fibres as quantum and conventional communications, this system achieves high entanglement fidelity.

Project results are good:

Over several days, the system maintained Clauser-Horne-Shimony-Holt (CHSH) S-values between 2.36 and 2.74 and entanglement fidelities between 85% and 99% Validating entanglement and allowing quantum applications requires a CHSH S-value greater than 2. The 60km network has near telecom-grade uptime with less than 1.5% downtime, demonstrating outstanding stability for real-world implementation. The Qunnect SRC generates a high rate of photon pairs at normal temperature, acting as the entanglement source and preventing fibre losses without cryogenics or regulated laboratory circumstances. Automated path-switching and polarisation correction provide stable quantum correlations over independent fibre paths without manual changes. Despite -42 dB attenuation over 82 kilometres, the network maintained usable pair rates.

These examples dramatically transform quantum networks from lab conditions to trustworthy, operational infrastructure. By defining operational standards for commercially viable quantum services using quantum photons and classical telecom traffic, the technique drastically lowers the cost and complexity of new fibre deployments.

Bearlin Q-like metropolitan networks and MEO-based global networks show that quantum networks can be integrated with current resources, enabling distributed quantum computing, secure quantum communication, and quantum sensing in urban and possibly global infrastructure.Automated path-switching and polarisation correction provide stable quantum correlations over independent fibre paths without manual changes. Despite -42 dB attenuation over 82 kilometres, the network maintained usable pair rates.

These examples dramatically transform quantum networks from lab conditions to trustworthy, operational infrastructure. By defining operational standards for commercially viable quantum services using quantum photons and classical telecom traffic, the technique drastically lowers the cost and complexity of new fibre deployments. Bearlin Q-like metropolitan networks and MEO-based global networks show that quantum networks can be integrated with current resources, enabling distributed quantum computing, secure quantum communication, and quantum sensing in urban and possibly global infrastructure.

[knowledge-wale]

Breakthrough in Quantum Computing: IBM's Eagle Processor

IBM recently unveiled a significant leap in quantum computing with its 127-qubit "Eagle" processor, marking a substantial technical milestone. Unlike traditional computers that use bits as 0s and 1s, quantum computers operate on qubits, which can exist in multiple states simultaneously, thanks to superposition. The Eagle processor surpasses the 100-qubit barrier, making it the most powerful quantum chip to date.

This leap brings us closer to quantum supremacy, where quantum machines can solve problems in seconds that would take classical computers thousands of years. IBM’s Eagle uses advanced architecture to reduce quantum errors, a major challenge in the field, and demonstrates an unprecedented capability to simulate complex molecules, which could revolutionize fields like drug discovery, cryptography, and artificial intelligence.

IBM aims to integrate this processor into its Quantum System One, offering cloud-based access for enterprises looking to harness quantum power. This development places quantum computing on the verge of real-world applications, promising breakthroughs in optimization problems, cryptographic systems, and AI training. https://www.knowledgewale.com/search/label/Technology

#quantumcomputing #ibmeagleprocessor #quantumbreakthrough #quantumtechnology #ibmquantum #eagleprocessor #quantumadvancements #quantumcomputingnews #quantuminnovation #quantumcomputing2024 #ibmresearch #quantumalgorithms #quantumchip #futureofcomputing #quantumhardware #highperformancecomputing #quantumleaps #quantumapplications #quantumresearch #quantumcomputers

[curelet-blog]

Designing new materials & discovery of new phases of matter are just few baby steps in finding applications of quantum entanglement. From Michele Mosca recent talk Security in the Quantum Future at Quantum-Nano Center @QUANTUMIQC @uofwaterloo. #quantumiqc #quantumapplications #newmaterials #quantum #entanglement #EntangledTheSeries @CityWaterloo #UWaterloo #pictureyourwaterloo #WaterlooPics #WRAwesome #KWAwesome #WaterlooRegion #waterloo #ontario #Canada🇨🇦 (at Mike & Ophelia Lazaridis Quantum-Nano Centre) https://www.instagram.com/p/B29SOV_Atu8/?igshid=l5x1u8res6g

[justin-aptaker]

via Twitter https://twitter.com/justin_aptaker

[govindhtech]

What is PEA, How Does PEA Work in Quantum Noise Mitigation

PEA: Probabilistic Error Amplification

This page explains PEA and how it works.

Probabilistic Error Amplification Improves Scalable Quantum Error Mitigation.

quantum computing has the potential to revolutionise complex problem-solving, but noisy hardware is still a major obstacle. Even while error-correcting codes solve the problem in the long run, near-term devices need error mitigation to limit noise and produce reliable output. A promising utility-scale quantum error mitigation solution is Probabilistic Error Amplification (PEA), a hybrid approach that promises accurate noise modelling without the complexity of conventional methods.

Error cancellation to amplification

Two main error mitigation methods have been used:

After learning noise behaviour, Probabilistic Error Cancellation (PEC) actively removes it in post-processing. Despite its theoretical ideality and impartiality, PEC's exponential sampling resource requirements make it unfeasible for moderate-sized circuits.

ZNE assesses outputs from purposely amplified noise and extrapolates back to find zero-noise. It is simpler to construct and more scalable than PEC, but inappropriate application compromises bias guarantees.

PEA combines ZNE's efficiency and scalability with PEC's accuracy and bias management.

PEA Works How?

PEA comprises three phases.

Noise-learning calibration

The system uses control circuits, commonly Pauli twirling, to characterise each layer of two-qubit gate noise. These calibration findings create a layered noise profile needed for further phases.

Probability-Based Amplification

At varied noise amplification levels, the algorithm re-executes the target quantum circuit. Instead of prolonging pulses or reproducing gates, PEA randomly injects noise based on the learning profile to reduce circuit depth and control error escalation.

Noiseless Extrapolation

Expectation values from various noise levels are fitted to a linear or exponential model and extrapolated to estimate the result in a noise-free condition.

This preserves ZNE's simpler, depth-friendly structure while retaining PEC's accuracy and avoiding its resource-intensive constraints.

The “Utility-Scale” of PEA

In real-world quantum circuits with tens to hundreds of qubits and deep circuit layers, gate-folding ZNE often fails due to gate-count overhead or incorrect noise scaling. PEC is impractical due of exponential sampling.

PEA is best-of-both-worlds because:

Preventing gate duplication: No circuit depth increase.

Statistical models and calibrated noise reduce sampling overhead.

Maintains bias control and produces unbiased estimators like PEC.

Scalability: Supports realistic circuit complexity.

IBM’s Qiskit Runtime includes PEA demonstrations for “utility-scale” circuits on 127-qubit machines, proving its suitability for real computing workloads.

Quantum Computing Implications

Scaling Near-Term Devices

PEA allows noise-limited circuits to function deeper and over more qubits, offering near-term quantum advantage.

Bridge to Fault Tolerance

Even while it cannot replace error correction, PEA reduces logical errors competitively, especially in cases of limited physical qubit resources.

Widening Algorithms

PEA improves VQE, QAOA, and quantum chemistry simulation accuracy without increasing hardware requirements.

Enhancing New Methods

Hybrid methods like tensor-network-based mitigation (TEM) combine PEA with post-processing for efficiency.

Looking Ahead

Continuous development and benchmarking shape PEA's trajectory:

PEA is being tested in dynamic circuits that integrate mid-circuit data and classical feedforward, formerly a PEC restriction.

Asymptotic sampling and PEA's ability to reduce bias at larger scales are validated by theoretical models.

PEA-ML-driven error reduction hybrid mediation strategies are being studied to dynamically react to hardware drift and noise fluctuations.

In conclusion

Probabilistic mistake Amplification improves error mitigation with precision, scalability, and efficiency. PEA uses smart extrapolation and anchoring error management in well-characterized noise behaviour to perform deeper, more accurate quantum computations without fault-tolerant hardware. As quantum processors increase, PEA's utility-scale promise may unlock real-world quantum advantage.