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Daily brief

August 18, 2026.

70 quantum research items collected on 2026-08-18; hardware, control, and industry signals routed.

115 items · Quantum, Chips, Power · All briefs

Quantum

70 quantum research items collected on 2026-08-18; hardware, control, and industry signals routed.

Hardware and Error Correction

  • Classical Adversarial Fault-Tolerance and PCPs

    We show how to compile an arbitrary classical circuit into a fault-tolerant circuit, which performs the desired computation even when an almost-linear number of bits are adversarially chosen and corrupted in each timestep. Using a variant of this fault-tolerance scheme that only detects (rather than corrects) corruptions, we give a new construction of probabilistically check...

  • Fault-Tolerant Quantum Computation with Adversarial Errors

    We prove a fault-tolerance theorem for quantum computation against adversarial noise. For every quantum circuit on $\bar{N}$ logical qudits of depth $\bar{T}$, we construct a fault-tolerant circuit on $N=\text{poly}(\bar{N})$ physical qudits of depth $\bar{T}\cdot\bar{N}^{o(1)}$, which is robust against an adversary who may arbitrarily choose and corrupt an almost-linear num...

  • Hundred-hertz quantum circuit iteration rate in a reusable neutral-atom array

    Neutral-atom quantum processors have rapidly advanced in scale and coherence, yet their practical performance remains constrained by limited quantum circuit iteration rates (qCIRs) and information throughput. Here we experimentally demonstrate a high-throughput neutral-atom system based on non-destructive readout and atom reuse. By integrating a chip-based photonic interface...

  • A nuclear-quantum-corrected machine-learning potential reveals quantum-enhanced hydrogen segregation at general grain boundaries in alpha-iron

    Atomistic descriptions of hydrogen diffusion and trapping at defects are essential for understanding hydrogen embrittlement. As the lightest solute in metals, hydrogen exhibits nuclear quantum effects that alter these processes even at room temperature. Explicit treatment of such effects is computationally demanding, limiting large-scale simulations of complex environments....

  • Scientific applications of quantum computing: challenges and opportunities

    The predictive simulation of molecules and materials has had a broad and significant impact. It nevertheless remains constrained by the cost of accurately treating electronic correlation, excited states, and complex energy landscapes. Quantum computing offers a fundamentally different computational paradigm in which quantum states are encoded and manipulated directly rather...

  • Non-invertible Lattice 1-Form Symmetries for Non-Abelian Topological Order

    Higher-form symmetries generalize conventional global symmetries and act on lower-dimensional submanifolds of a quantum system. While Abelian topological phases can be organized by 1-form symmetries that form a group, non-Abelian topological phases based on finite groups require 1-form symmetry operators governed by non-invertible fusion algebras. In this work, we make this...

  • Quantum Mpemba Speedups in the Thermodynamics of Landauer Erasure

    We investigate how nonequilibrium quantum initial states can reduce the finite-time thermodynamic cost of Landauer erasure. Considering a general finite-dimensional quantum memory coupled to a thermal reservoir via a Davies generator, we show that the dissipated heat at a fixed operational erasure fidelity is largely controlled by the overlap of the initial state with the sl...

  • Half a qubit: an algebraic fractionalization

    Fractionalizing a quantum two-level system is usually associated with encodings based on pairs of Majorana fermions---an operational fractionalization. We show an alternative algebraic fractionalization by embedding Székely's classical ``half-coin'' into a non-Hermitian Krein space. The coefficients of $(q+pz)^{1/2}$ define a signed sequence and a normalized, non-Hermitian b...

Control and Quantum-AI Integration

  • Scalable nuclear shell model calculations on noisy quantum computers

    The exact diagonalization of the nuclear shell model scales exponentially, leading to severe memory bottlenecks in classical high-performance computing (HPC). While hybrid quantum algorithms like the Variational Quantum Eigensolver (VQE) aim to overcome these limits, their deep quantum circuits and iterative feedback loops are susceptible to substantial noise inherent in the...

  • Optimizing Subspace Expansion in Quantum Chemistry through Operator Selection and Reference State Choice

    The Virtual Quantum Subspace Expansion (VQSE) extends the Variational Quantum Eigensolver (VQE) by leveraging additional measurements on the reference state to capture the influence of excluded virtual orbitals. This makes VQSE attractive for chemical applications where accurate energy differences along potential energy surfaces are crucial for modeling reaction rates and ki...

Commercial and Industry Context

Unrouted Items

  • Spectral Edge Rigidity of Quantum Chaotic States

    We determine the distribution of fidelity susceptibility for chaotic eigenstates at the spectral edge of Gaussian random-matrix ensembles. Previous work showed that, in the unitary class, the characteristic susceptibility scale of edge states grows as $D^{1/3}$, rather than proportionally to $D$ as in the spectral bulk, reflecting Airy-edge level rigidity. Extending a determ...

  • Global Minimax Readout of a Qubit Direction

    We determine the exact worst-direction Fisher-information cost of using a parameter-independent readout to estimate an unknown qubit direction at known Bloch-vector length $η$. Every fixed-local architecture, including recorded classical randomization, heterogeneous single-copy measurements, and arbitrary outcome spaces, reduces exactly to a zero-barycenter probability measu...

  • Classical-limit formula for matrix elements between bound states of distinct one-dimensional potentials

    A classical-limit formula is derived for matrix elements between bound states of distinct one-dimensional potentials. We leave open the physical interpretation of the potentials, but generally envision them to be Born-Oppenheimer-type potentials with the position variable $x$ identifying with a slowly evolving degree of freedom of the system. For instance, $x$ could represen...

  • Quantum Simulation of QCD in Axial Gauge

    We study quantum simulation of SU(3) non-Abelian gauge theory dynamically coupled with fundamental fermions in $3+1$ dimensions by employing the lattice Hamiltonian in axial gauge that avoids Gauss's law constraints. The temporal component of the gauge field is analytically solved in terms of independent field degrees of freedom and a lattice regulated Green's function. The...

  • The preferred-time problem in the conditional interpretation of time

    In timeless formulations of quantum theory, the Page-Wootters proposal (PW) recovers time and dynamics as relative clock-and-world states. By interpreting the total timeless system as a clock entangled with the world, the states having a definite clock reading appear to recover the temporal states of the world as relative states, and dynamics emerges. But an entangled state...

  • Exact mobility rings in non-Hermitian quasiperiodically decorated Lieb lattices

    The mobility ring (MR), a critical boundary in the complex energy plane separating extended and localized states, is fundamental to understanding the Anderson transition in non-Hermitian (NH) disordered systems. While MRs have been extensively studied in one-dimensional (1D) NH quasiperiodic models, rigorous analytical frameworks beyond 1D remain critically scarce. Here, we...

  • Engineering two-qubit gates via anisotropic exchange in germanium spin qubits

    Germanium hole spin qubits are a promising and versatile platform for quantum computation and simulation. In this system, strong spin-orbit interaction (SOI) renders the single-qubit $g$-tensor anisotropic and electrically tunable, enabling operational sweet spots with reduced noise sensitivity. SOI also transforms the isotropic two-qubit exchange coupling into an anisotropi...

  • Time-optimal quantum gates with bang-bang control in multilevel systems

    We determine the optimal quantum manipulation protocols for implementing high-fidelity, fast single-qubit gates. We demonstrate that the time-optimal pulse sequence is a ``bang-bang'' sequence: discrete pulses of either positive or negative maximum amplitude or zero. The non-adiabatic bang-bang pulse sequence minimizes gate duration providing a speedup for low-frequency arch...

  • Superposition of dynamics, indefinite causal order, and quantum histories

    The process-matrix formalism describes quantum processes without assuming a fixed global causal order, but the physical meaning of indefinite causal order remains open. We address this question within histories theory, where temporal ordering and dynamical evolution are distinct structures. We show that the decoherence functional admits coherent superpositions of dynamics. I...

  • Crossover from Fast Scrambling to Operator Confinement Tuned by an Auxiliary Qubit

    We demonstrate a static, disorder-free spin chain Hamiltonian which, by tuning the coupling to an auxiliary qubit, realizes a crossover between super-ballistic, ancilla-accelerated scrambling and sub-ballistic operator confinement. Our minimal model is the mixed-field Ising chain with a spin-1/2 ancilla coupled to its longitudinal magnetization. The ancilla mediates an effec...

  • Sensitivity Scaling and Limits of Cavity Enhancement in Miniaturized Optically Pumped Magnetometers

    The sensitivity of miniaturized optically pumped magnetometers (OPMs) is limited by weak atom-light coupling, which an optical cavity can enhance. In this work, we model the photon-shot-noise-limited sensitivity of cavity-enhanced OPMs in the regime of strongly collisionally broadened optical transitions, characteristic of buffer-gas-filled miniaturized vapor cells. The cavi...

  • Quench Spectroscopy for Two-Dimensional Spin Models with Power-Law Interactions

    In this paper, we analytically compute the quench dynamics of simple product states that evolve under a spin-1/2 XY-model with power-law interactions in a staggered magnetic field. We use linear spin-wave theory as well as a low-energy theory that accounts for strong phase fluctuations. This allows us to provide an analytic expression for the dynamics of phase-type correlati...

  • Carnot Meets Quantum Information: Thermal Machine Driven by Probabilistic Non-orthogonal State Discrimination

    While the impossibility of perfectly identifying non-orthogonal states is a cornerstone of quantum information science, their probabilistic discrimination is nonetheless permissible. Here, we propose a two-reservoir quantum machine driven by this mechanism to map its functional boundaries across the parameter space of the state overlap $μ$ and the Carnot efficiency $η_C$. Wi...

  • On Casimir force between two real metallic plates

    The corrections to Casimir pressure (force) on two plates of real metal described by the dielectric constant of the Drude, Drude-Lorentz, Drude-Smith and plasma models at the finite temperature and conductivity are considered. We consider the contour integral lost in the Lifshitz formula and discuss inconsistencies for the corrections to the Casimir force given in the litera...

  • Scarred discrete time crystal in a periodically driven dimerized spin chain

    We investigate the emergence of a scarred discrete time crystal (SDTC) phase in a periodically driven dimerized spin chain. While generic interacting Floquet systems are expected to thermalize according to the eigenstate thermalization hypothesis (ETH), we demonstrate that this system hosts quantum many-body scars (QMBS) that induce a regime of weak ergodicity breaking. Thro...

  • Discretisation of quantum feedback networks for implementation on a quantum computer

    Quantum Feedback Network Theory (also known colloquially as the SLH-framework) is a powerful tool for modeling systems in quantum optics. This paper describes a method for discretising SLH-networks such that they can be implemented on a quantum computer. Building on a discretisation theorem for quantum stochastic differential equations, we establish strong convergence, unifo...

  • Krylov complexity of anyons

    Anyons obey fractional statistics that lie between bosonic and fermionic statistics, giving rise to a broad range of intriguing phenomena. However, how anyonic statistics govern quantum-state complexity is still largely unexplored. In this work, we investigate the interplay between the statistical phase and on-site interactions in the anyon-Hubbard model, identifying exact q...

  • Evidence for cavity-induced metallic phase from entropic electron correlation effects

    Experiments have revealed that collective strong coupling in optical cavities can drastically alter the conductivity and dielectric properties of molecular ensembles, or even trigger abrupt phase transitions (in Rayleigh scattering or dispersion force driven conformational equilibrium). Until now, the underlying physical mechanism has remained unknown. A recently proposed th...

  • Casimir force between plane-layered structures: van Kampen-Schram approach for finite temperature

    Based on the van Kampen-Schram method, a formula for the Casimir force between two plane-layered structures is obtained, which includes the sum of the Matsubara frequencies and a contour integral. It is shown that the contour integral is not taken into account in the Lifshitz formula. Taking it into account gives a small contribution at high temperatures when the Lifshitz fo...

  • Imaginary Barrier, Real Transfer: Non-Hermitian Dynamical Tunnelling

    We identify a non-Hermitian counterpart of dynamical tunnelling induced by a localised absorbing region in a symmetric confining potential. The absorbing region, described by an imaginary potential barrier, induces an effective double-well structure with a pair of long-lived states that have little population in the barrier. In contrast to the periodic tunnel oscillations th...

  • Quantum Permutations and Beyond Quantum Controlled Reference Frames

    Quantum permutations, or magic unitaries, have in recent years been explored in the context of identifying `genuinely quantum' isometries of graphs. Here, we import this tool in physics, showing that quantum permutations yield a generalisation of quantum reference frames in a discrete setting that is reminiscent of the passage from special to general relativity. We show that...

  • Two-Photon Bound States in the Continuum: A No-Go Theorem and Long-Lived Quasi-Bound States

    Two-photon bound states in the continuum provide a stringent setting in which quantum interference must suppress radiative decay despite photon--photon interactions. Here, we prove a no-go theorem showing that a single nonlinear mode linearly coupled to a noninteracting bosonic continuum cannot support an interaction-active two-photon bound state in the continuum, provided t...

  • Spectral filtering and crystal length as control parameters for conditional correlations in quantum imaging

    We establish spectral filtering as a control parameter for the conditional momentum and position correlations of SPDC biphotons used in quantum imaging. The conditional momentum uncertainty in spontaneous parametric down-conversion (SPDC) is strongly crystal-length and spectral-filter dependent along the walk-off axis; therefore, the effect is observed only in critically pha...

  • MoMPy: automated construction of moment matrices for semidefinite programming relaxations

    We present MoMPy, an open-source Python package that provides a unified, declarative construction of moment matrices for semidefinite programming (SDP) hierarchies. The user declares operator labels together with a small set of structural relations, and MoMPy returns a matrix of SDP variable indices in which every implied identification has already been made, ready for CVXPY...

  • The Unidirectional Current as First Arrival-Time POVM: An MS-Kijowski Identity, Physical Interpretation, and Mathematical Applications

    Detector-based first-arrival models and operator-based arrival-time observables provide two conceptually distinct approaches to the quantum time-of-arrival problem. Here we connect these approaches by using the positive unidirectional first-arrival current of Marchewka and Schuss (MS) as the basis for constructing a family of positive arrival-time operators and, after normal...

  • Quantum gate lower bounds for loss-tolerant position verification

    Quantum position-verification is a cryptographic task wherein a verifier attempts to establish the location in space of a prover. Recent experiments have implemented a well-studied class of position-verification schemes, known as the $f$-BB84 scenario, but their security under realistic loss and imperfect state preparation remains incompletely understood. We give a new lower...

  • Strong Converse Exponents of Quantum Soft Covering and Privacy Amplification

    We determine the exact strong converse exponent of quantum soft covering under the sandwiched R{é}nyi divergence for all orders $α\in[\frac{1}{2},\infty)$. For $α\in[\frac{1}{2},1)$, the exponent is characterized by the two-parameter club-sandwiched mutual information, whereas for $α\in[1,\infty)$, it is characterized by the order-$α$ sandwiched R{é}nyi mutual information. W...

  • Optimal bounds on the classical value of the repeated CHSH game

    We show that the maximum winning probability in the repeated CHSH game for classical strategies is at most $\left(\frac{1+\sqrt{5}}{4}\right)^n$. Together with a matching lower bound by Barak et al. (FOCS'2008), this determines the asymptotic value of the repeated CHSH game exactly. We also show that, if an XOR game has a gap between classical and quantum values, there is al...

  • Negative quasiprobability trajectories for Bell-diagonal states under local decoherence

    The fluctuation theorem (FT) relates microscopic trajectory distributions to macroscopic averages. Using quasiprobability trajectories, this framework has recently been extended to quantum information dynamics. Despite sharing the form of conventional thermodynamic FTs, information FTs involve quasiprobabilities whose negativity and statistical properties remain poorly under...

  • Quantum Wave-Particle Duality in Free-Electron--Free-Electron Entanglement

    Point-particle descriptions of electron-electron interaction omit the coherent longitudinal extent of a free-electron quantum wave packet (QEW). A relativistic two-electron wave-packet theory identifies the longitudinal QEW size as a direct control parameter for entanglement generated by mutual electromagnetic coupling. For two electrons in spatially separated paths, the qua...

  • Controlling rotations of magnetically levitated superconductors

    Magnetically trapped type-I superconductors are promising candidates for precision experiments at the quantum-to-classical borderline, with applications in quantum sensing of forces and accelerations and fundamental tests of quantum physics. Here, we show how the rotational motion of micron-sized superconductors is strongly affected by (i) the diamagnetic torques due to the...

  • Quantum Rabi oscillations of a qubit strongly coupled to a one-dimensional waveguide

    We theoretically investigate quantum Rabi oscillations in a system consisting of a two-level atom (qubit) strongly coupled to a one-dimensional open waveguide. In contrast to conventional cavity quantum electrodynamics, the qubit interacts with a continuum of propagating modes, which gives rise to fundamentally different dynamical behavior. Within the rotating-wave approxima...

  • zenDot: An LLM-integrated quantum TCAD platform for semiconductor quantum-device design and optimization automation

    Semiconductor quantum-device design still lacks an integrated Technology Computer-Aided Design (TCAD)-like environment that connects material geometry, quantum many-body simulation, and automated design. Here we introduce zenDot, a large-language model (LLM)-integrated quantum TCAD platform that links a material-labelled device state to a unified condensed-matter physics too...

  • Transport-Noise Witnesses of Electronic Multipartite Entanglement

    Entanglement among particles is a defining feature of strongly correlated quantum materials, distinguishing them from conventional metals and semiconductors. The ability to certify intrinsic entanglement among interacting electrons in solid-state materials is important not only for classifying quantum states of matter, but also for developing material-based quantum technolog...

  • Sub-cycle metrology of bright quantum light

    In quantum optics, quantization of the electromagnetic field typically occurs in a finite volume - a cavity - which results in discrete frequency modes where photons are created, annihilated and exchanged between such modes. As a result, evolution of quantum optical states is periodic in the carrier wave of the field, measurement protocols return cycle-averaged information,...

  • Who’s News: Strategic Appointments at PsiQuantum, EigenQ, Qunova Computing, and Optica Quantum

    <p>PsiQuantum has appointed Niklas Zennström to its Board of Directors, effective August 11, 2026. Zennström is the Founder and CEO of Atomico and co-founder of Skype. He succeeds Siraj Khaliq as Atomico's representative on the board, following recent executive additions including Victor Peng as CEO, Rob Soderbery as Executive Vice President, and Sriram Sitaraman as [...]</p...

  • Rice University Researchers Engineer Tunable Finite-Temperature Reservoirs in Trapped-Ion Quantum Simulators

    <p>https://youtu.be/GKTP7OULWb4 Physicists at Rice University have developed an experimental reservoir-engineering scheme that introduces independently tunable temperatures and dissipation rates to the vibrational modes of a trapped-ion quantum simulator. Published in Physical Review Letters ("Experimental Realization of Thermal Reservoirs with Tunable Temperature in a Trapp...

  • Tamil Nadu Secures MoUs with Four Quantum Computing Ventures at Vetri Conclave

    <p>The Government of Tamil Nadu has signed Memoranda of Understanding (MoUs) with four quantum technology ventures during the Vetri Tamil Nadu Investment Conclave 2026 in Chennai. The strategic agreements establish operational bases, R&amp;D centers, and control system manufacturing facilities across the state, strengthening India's regional quantum hardware and software eco...

  • Sydney Quantum Academy Hosts Event to Introduce Students to Quantum Careers

    <a href="https://thequantuminsider.com/2026/08/18/sydney-quantum-academy-event-quantum-careers/" rel="nofollow" title="Sydney Quantum Academy Hosts Event to Introduce Students to Quantum Careers"><img alt="Sydney Quantum Academy logo" class="webfeedsFeaturedVisual wp-post-image" height="671" src="https://thequantuminsider.com/wp-content/uploads/2026/08/2026-08-18_14-12.png"...

  • Community Groups Want Mayor to Shut Down Quantum Shore Chicago Project

    <a href="https://thequantuminsider.com/2026/08/18/community-groups-want-mayor-to-shut-down-quantum-shore-chicago/" rel="nofollow" title="Community Groups Want Mayor to Shut Down Quantum Shore Chicago Project"><img alt="community over quantum" class="webfeedsFeaturedVisual wp-post-image" height="1080" src="https://thequantuminsider.com/wp-content/uploads/2026/08/Screenshot-20...

  • Researchers Use Light to Study Electron Motion in Wigner Crystals

    <a href="https://thequantuminsider.com/2026/08/18/researchers-use-light-study-electron-motion-wigner-crystals/" rel="nofollow" title="Researchers Use Light to Study Electron Motion in Wigner Crystals"><img alt="The researchers used light to reveal the collective motion of electrons forming a Wigner crystal. (Illustration: Enrique Sahagún, Scixel / University of Basel, Depart...

  • China Tests Quantum Technology in Power Grid

    <a href="https://thequantuminsider.com/2026/08/18/china-tests-quantum-technology-in-power-grid/" rel="nofollow" title="China Tests Quantum Technology in Power Grid"><img alt="China Substation" class="webfeedsFeaturedVisual wp-post-image" height="683" src="https://thequantuminsider.com/wp-content/uploads/2026/08/China-Substation.jpg" style="display: block; margin: auto; margi...

  • From Beaches to Bits to Qubits – Silicon’s Journey in Quantum Computing

    <a href="https://thequantuminsider.com/2026/08/17/from-beaches-to-bits-to-qubits-silicons-journey-in-quantum-computing/" rel="nofollow" title="From Beaches to Bits to Qubits &#8211; Silicon’s Journey in Quantum Computing"><img alt="" class="webfeedsFeaturedVisual wp-post-image" height="326" src="https://thequantuminsider.com/wp-content/uploads/2026/08/9c28a013-2af1-47ee-81de...

  • Study Deepens Understanding of Quantum Transport in Topological Materials

    <a href="https://thequantuminsider.com/2026/08/17/study-deepens-understanding-of-quantum-transport-in-topological-materials/" rel="nofollow" title="Study Deepens Understanding of Quantum Transport in Topological Materials"><img alt="topological" class="webfeedsFeaturedVisual wp-post-image" height="568" src="https://thequantuminsider.com/wp-content/uploads/2026/08/Low-Res_qua...

Chips

46 chip stack items collected on 2026-08-18; memory, packaging, compute, and foundry signals routed.

Compute Accelerators

Memory and Advanced Packaging

  • Chip Industry Technical Paper Roundup: Aug. 18

    <p>2D CFET scaling; PIM chiplet voltage-droop control; advanced-node layout repair; lithography defect prediction; 3D-IC failure analysis; chiplet and interposer optimization; 4H-SiC wafer slicing.</p> <p>The post <a href="https://semiengineering.com/chip-industry-technical-paper-roundup-aug-18/">Chip Industry Technical Paper Roundup: Aug. 18</a> appeared first on <a href="h...

  • Controlling Voltage Droop In 2.5D PIM Chiplet Architectures (Washington St., UW-Madison)

    <p>Researchers from Washington State University and University of Wisconsin–Madison published a technical paper titled “ReVolt: Power Delivery Network-Aware Voltage Droop Control for 2.5D PIM Chiplet Architectures.” Abstract “Processing-in-memory (PIM)-based 2.5D multi-chiplet platforms are enablers for machine learning (ML) workloads. However, their performance is affected...

Custom Silicon and Networking

  • Copper’s Grip On AI Scaling Is Starting To Slip

    <p>As AI clusters push beyond rack-scale limits, optical interconnects and circuit switching are reshaping how data centers scale. </p> <p>The post <a href="https://semiengineering.com/coppers-grip-on-ai-scaling-is-starting-to-slip/">Copper’s Grip On AI Scaling Is Starting To Slip</a> appeared first on <a href="https://semiengineering.com">Semiconductor Engineering</a>.</p>

Foundry, Tools, and Capex

Unrouted Items

Power

19 power layer items collected on 2026-08-18; data center load, grid, generation, and cooling signals routed.

Data Center Power Demand

  • Battery storage capacity averaged 70% growth over the last three years

    Utility-scale battery storage capacity in the United States increased significantly during the last three years, with an annual average growth rate of 70%. By the end of 2025, the U.S. power system had operational battery storage capacity of 43.6 gigawatts (GW). During the first six months of 2026, operators added another 8.3 GW of battery storage capacity, reaching nearly 5...

  • New York imports more electricity from Canada after high-voltage transmission line opens

    On July 3, 2026, the New York Independent System Operator (NYISO) imported 52 gigawatthours (GWh) of electricity from Canada, the most traded between the two areas since January 2025. Some of the imported electricity flowed along the new Champlain Hudson Power Express (CHPE) transmission line between Quebec, Canada, and New York City, which officially reached commercial oper...

Grid and Generation

Unrouted Items

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