The Schrodinger cat's Post

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Device-independent quantum key distribution over 100 km with single atoms Device-independent quantum key distribution (DI-QKD) is a key application of the quantum internet. We report the realization of DI-QKD between two single-atom nodes linked by 100-km fibers. To improve...

A new work demonstrates quantum key distribution between two single-atom nodes separated by up to 100 km of fiber. They obtain positive secure key rates, marking a significant step toward practical quantum internet applications.
arxiv.org/abs/2602.09596

Empirical Evaluation of QAOA with Zero Noise Extrapolation on NISQ Hardware for Carbon Credit Portfolio Optimization in the Brazilian Cerrado Optimizing carbon credit portfolios is a critical challenge for climate mitigation, particularly in high-biodiversity biomes such as the Brazilian Cerrado. This study explores the practical applicatio...

A new paper applies QAOA with Zero Noise Extrapolation to optimize a carbon credit portfolio, balancing carbon sequestration, biodiversity, and social impact. The quantum workflow significantly outperforms a classical greedy baseline (≈32% improvement)
arxiv.org/abs/2602.09047

Surface code off-the-hook: diagonal syndrome-extraction scheduling In the rotated surface code, hook errors (errors on auxiliary qubits midway through syndrome extraction that propagate to correlated two-qubit data errors) can reduce the circuit-level code distance b...

In the rotated surface code, poorly chosen syndrome extraction schedules can cause hook errors that align with logical operators. The proposed diagonal schedule orients hook errors along plaquette diagonals.
arxiv.org/abs/2602.09099

In today's edition:
- #Quantum key distribution over 100 km
- Quantum optimization for environment
- Surface code improvement

More details and links below:

That’s it for the daily selection. If you enjoyed it, please consider giving me a like or reposting to support my content. Thanks! (Remember that these papers are published on arXiv before undergoing any peer review.)

A building block of quantum repeaters for scalable quantum networks Quantum networks, integrating quantum communication, quantum metrology, and distributed quantum computing, could provide secure and efficient information transfer, high-resolution sensing, and an expo...

Combining long-lived trapped-ion quantum memories with efficient telecom interface led to establish stable memory-memory entanglement over 10 km. This enables the first metropolitan-scale device-independent quantum key distribution.
arxiv.org/abs/2602.08472

BiBiEQ: Bivariate Bicycle Codes on Erasure Qubits Erasure qubits reduce overhead in fault-tolerant quantum error correction (QEC) by converting dominant faults into detectable errors known as erasures. They have demonstrated notable improvements in t...

BiBiEQ is a framework to integrate erasure qubits into Bivariate Bicycke QLDPC codes. Erasure-aware decoding is shown to significantly decrease logical error rates. Furthermore, most performance gains are already achieved by moderate code distances.
@kanadbasu.bsky.social
arxiv.org/abs/2602.07578

Non-Markovianity induced by Pauli-twirling Noise forms a central obstacle to effective quantum information processing. Recent experimental advances have enabled the tailoring of noise properties through Pauli twirling, transforming arbitrary n...

Pauli twirling, while simplifying noise into Pauli channels, can turn Markovian noise into non-Markovian noise. This can affect the performance of some quantum error mitigation and correction.
arxiv.org/abs/2602.08464

Hybrid Method of Efficient Simulation of Physics Applications for a Quantum Computer Quantum chemistry and materials science are among the most promising areas for demonstrating algorithmic quantum advantage and quantum utility due to their inherent quantum mechanical nature. Still, l...

A new paper introduces a hybrid classical simulator that combines full state and Clifford simulators to efficiently emulate multi-qubit Pauli rotations. This approach dramatically accelerates the simulation of quantum chemistry circuits.
arxiv.org/abs/2602.09020

Quantum Charging Advantage in Superconducting Solid-State Batteries Quantum battery, as a novel energy storage device, offers the potential for unprecedented efficiency and performance beyond the capabilities of classical systems, with broad implications for future qu...

A chain of superconducting qubits can be charged faster and more efficiently using a quantum interactions. This demonstrates a scalable quantum advantage in energy storage.
arxiv.org/abs/2602.08610

In today's edition:
- #Quantum charging advantage for battery
- Memory-memory entanglement over 10 km
- Hybrid Clifford-Fullstate simulator
- Induced non-Markovianity
- QLDPC code with erasure qubits

More details and links below:

That’s it for the daily selection. If you enjoyed it, please consider giving me a like or reposting to support my content. Thanks! (Remember that these papers are published on arXiv before undergoing any peer review.)

Characterizing Quantum Error Correction Performance of Radiation-induced Errors Radiation impacts are a current challenge with computing on superconducting-based quantum devices because they can lead to widespread correlated errors across the device. Such errors can be problemati...

Radiation can cause correlated errors in superconducting quantum devices that standard error correction struggles to handle. A simulation framework modeling these effects allows testing of quantum error correction codes and chip designs.
arxiv.org/abs/2602.06202

Quantum-controlled synthetic materials Analog quantum simulators and digital quantum computers are two distinct paradigms driving near-term applications in modern quantum science, from probing many-body phenomena to identifying computation...

Hybrid digital-analog quantum control enables the creation of novel strongly correlated states, including photons in superpositions of solid and fluid phases, and stabilizes entangled cat states with enhanced coherence.
arxiv.org/abs/2602.06108

Warm Starts, Cold States: Exploiting Adiabaticity for Variational Ground-States Reliable preparation of many-body ground states is an essential task in quantum computing, with applications spanning areas from chemistry and materials modeling to quantum optimization and benchmarki...

Instead of trying to find directly the ground state of a complex system with traditional VQE, a new method gradually deforms the Hamiltonian through a sequence of intermediate steps.
@pvricard.bsky.social, @qzoeholmes.bsky.social
arxiv.org/abs/2602.06137

Extensible universal photonic quantum computing with nonlinearity Universal quantum computing requires an architecture that supports both linear circuits and, crucially, strong nonlinear resources. For quantum photonic systems, integrating such nonlinearities with s...

An extensible photonic quantum computer that combines scalable linear optical circuits with integrated nonlinear modules enables a universal set of quantum gates. The authors generate GKP states for error correction.
arxiv.org/abs/2602.06544

Quantum Attention by Overlap Interference: Predicting Sequences from Classical and Many-Body Quantum Data We propose a variational quantum implementation of self-attention (QSA), the core operation in transformers and large language models, which predicts future elements of a sequence by forming overlap-w...

A new work introduces Quantum Self-Attention, a quantum version of the transformer operation that uses quantum interference to model sequence dependencies and output a loss directly ad a quantum measurement.
arxiv.org/abs/2602.06699

High-speed phase-encoded quantum secure direct communication over 11.4 km heterogeneous free-space and fiber links Robust quantum transmission is driving a new paradigm in space-ground quantum networking. Although phase encoding has been widely adopted in terrestrial fiber channels, it has long been considered uns...

Phase-encoded quantum communication, previously thought unsuitable for free space, can reliably transmit quantum signals over 1.4 km of urban air. This results suggest this approach could enable satellite-to-ground quantum links.
arxiv.org/abs/2602.06624

In today’s edition:
- #Quantum communication in free space
- Quantum self-attention mechanism
- Universal photonic quantum computing
- Iterative variational quantum algorithms
- Quantum-controlled synthetic materials
- Correlated error effect on QEC

More details and links below:

That’s it for the daily selection. If you enjoyed it, please consider giving me a like or reposting to support my content. Thanks! (Remember that these papers are published on arXiv before undergoing any peer review.)

Scalable testing of quantum error correction The standard method for benchmarking quantum error-correction is randomized fault-injection testing. The state-of-the-art tool \stim is efficient for error correction implementations with distances of...

A new work introduces a scalable benchmarking method for quantum error correction that combines stratified fault injection with extrapolation to efficiently estimate logical error rates beyond the limits of standard randomized testing.
arxiv.org/abs/2602.04921

Photonic entanglement enhanced multidimensional spectroscopy for probing exciton correlations: theory and applications to photosynthetic aggregates Nonlinear spectroscopic techniques using entangled photon pairs provide an opportunity to exploit non-classical correlations encoded in two-photon wavefunctions to manipulate two-exciton wavefunctions...

Simulations show that, compared to classical laser pulses, entangled photons more effectively isolate excited-state absorption pathways and reveal one- and two-exciton resonances with signals that scale linearly in intensity.
arxiv.org/abs/2602.05080

Advanced Quantum Communication and Quantum Networks -- From basic research to future applications Classical communication is the basis for many of our current and future technologies, such as mobile phones, video conferences, autonomous vehicles and particularly the internet. In contrast, quantum ...

A new review surveys the fundamental principles and architectures of quantum communication networks, highlighting how quantum mechanics enables advantages in security, sensing, and distributed quantum computing beyond classical communication.
arxiv.org/abs/2602.05781

Quantum Error Mitigation at the pre-processing stage The realization of fault-tolerant quantum computers remains a challenging endeavor, forcing state-of-the-art quantum hardware to rely heavily on noise mitigation techniques. Standard quantum error mit...

A new paper proposes a pre-processing quantum error mitigation strategy that replaces expensive post-measurement correction. By using tensor networks to efficiently compute a surrogate observable, the method avoids tomography and heavy post-processing.
arxiv.org/abs/2602.05916

#Quantum article selection of today:
- New quantum error mitigation
- Review on quantum communications
- Photonic entanglement enhanced spectroscopy
- Scalable testing of quantum error correction

More details and links:

That’s it for the daily selection. If you enjoyed it, please consider giving me a like or reposting to support my content. Thanks! (Remember that these papers are published on arXiv before undergoing any peer review.)

Detailed, interpretable characterization of mid-circuit measurement on a transmon qubit Mid-circuit measurements (MCMs) are critical components of the quantum error correction protocols expected to enable utility-scale quantum computing. MCMs can be modeled by quantum instruments (a type...

A new framework allows the analysis of mid-circuit measurement errors by decomposing experimentally reconstructed quantum instruments into elementary error processes. This enables detailed diagnosis and optimization of measurements in superconducting qubit devices.
arxiv.org/abs/2602.03938

Review of Superconducting Qubit Devices and Their Large-Scale Integration The superconducting qubit quantum computer is one of the most promising quantum computing architectures for large-scale integration due to its maturity and close proximity to the well-established semi...

A new review surveys superconducting qubit quantum computers, highlighting their strong prospects for scalable quantum computing.
arxiv.org/abs/2602.04831

Thermal State Simulation with Pauli and Majorana Propagation We introduce a propagation-based approach to thermal state simulation by adapting Pauli and Majorana propagation to imaginary-time evolution in the Schrödinger picture. Our key observation is that hig...

High-temperature quantum thermal states can be efficiently classically simulated by evolving sparse Pauli or Majorana operator expansions in imaginary time.
@quantummanuel.bsky.social, @aangrisani.bsky.social, @pvricard.bsky.social, @qzoeholmes.bsky.social
arxiv.org/abs/2602.04878