Chalmers University Demonstrates Hardware-Level Microwave Crosstalk Suppression via Parasitic Capacitance Engineering

quantumcomputingreport.com Oct 31, 2026

Chalmers University Demonstrates Hardware-Level Microwave Crosstalk Suppression via Parasitic Capacitance Engineering

Curated by Shubham · TechCapsules · Oct 31, 2026

AI-summarised brief · reviewed before publication

Physicists at Chalmers University of Technology demonstrated a new layout technique that eliminates classical microwave drive crosstalk in superconducting processors by engineering on‑chip parasitic capacitances. The preprint shows that crosstalk suppression arises from multi‑path destructive interference among parasitic capacitive channels, not from cancelling exchange coupling. Using a test chip with two floating transmons and a tunable coupler, the team found the optimal crosstalk‑null frequency 300 MHz away from the Jeff = 0 point. Floating transmons offer lithographic flexibility, and the method aligns classical crosstalk nulls with quantum ZZ nulls at the same flux bias.

💡 Why It Matters

· By decoupling crosstalk suppression from exchange coupling, the technique sidesteps stringent fabrication tolerances, enabling more reliable scaling of multi‑qubit superconducting circuits.

Capsules Quantum Computing

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Wolfspeed Commercializes Transparent Silicon Carbide Substrates for Quantum Computing and Integrated Photonics

Wolfspeed Inc. has launched commercial optical‑grade transparent silicon carbide (TSiC™) wafers, offering 150 mm and 200 mm substrates with 300 mm samples. The single‑crystal 4H‑SiC material targets quantum computing, integrated photonics, and cryogenic packaging, providing a scalable platform for solid‑state spin qubits and low‑loss photonic circuits. With optical absorption ≤ 0.05 cm⁻¹ across visible wavelengths, high refractive index, and excellent thermal conductivity, the wafers enable monolithic integration of spin defects, waveguides, and photon routing. The availability addresses long‑standing wafer‑scale bottlenecks that limited wide‑bandgap quantum devices and positions SiC as a viable alternative to diamond for large‑area quantum hardware.

💡 By delivering wafer‑scale, optical‑grade SiC, Wolfspeed removes a critical fabrication hurdle, allowing quantum developers to mass‑produce spin‑photon nodes with standard semiconductor tools. This shift could accelerate the transition from laboratory prototypes to commercially viable quantum processors.

quantumcomputingreport.com · Oct 31

IP Law Firm MBHB Launches Dedicated Quantum, Optics, and Semiconductors Practice Group…

Intellectual property firm McDonnell Boehnen Hulbert & Berghoff LLP (MBHB) has launched a dedicated Quantum, Optics, and Semiconductors Practice Group in Chicago. The new team will advise hardware developers, research universities, and government contractors as the Illinois Quantum and Microelectronics Park (IQMP) expands, with anchor tenants like PsiQuantum and IBM deploying commercial quantum infrastructure. The practice focuses on patent eligibility under 35 U.S.C. § 101, emphasizing physical apparatus claims over abstract algorithms, and addresses federal march‑in rights and export controls tied to public funding.

💡 By aligning legal expertise with the region’s quantum‑hardware boom, MBHB positions itself to shape how emerging technologies secure intellectual property and navigate complex regulatory landscapes.

quantumcomputingreport.com · Oct 31

pQCee Enters U.S. Public Sector Through Carahsoft Master Aggregator Agreement

pQCee Pte Ltd has signed a master aggregator agreement with Carahsoft Technology Corp., the leading U.S. government IT distributor, to sell its post‑quantum encryption software to federal, state, municipal, education and health‑care customers. Carahsoft will move pQCee’s suites through its reseller network and existing cooperative purchasing contracts, offering a drop‑in layer that implements NIST‑approved post‑quantum algorithms without replacing legacy systems. The partnership responds to Executive Order 14412, which obligates agencies to migrate high‑value assets away from vulnerable public‑key cryptography by set milestones. Because full architectural overhauls are financially prohibitive, agencies are seeking affordable, interoperable solutions that maintain operational continuity. Detailed procurement information is available on the Carahsoft pQCee Solutions Portal and in the company’s press release for immediate adoption today.

💡 Plugging a quantum‑ready encryption layer into existing infrastructure lets agencies meet federal deadlines without costly system rebuilds, fast‑tracking the nation’s shift to post‑quantum security.

thequantuminsider.com · Oct 31

Julien Camirand Lemire (Nord Quantique): One Cavity, One Error-Corrected Qubit

Julien Camirand Lemire, co‑founder and CEO of Canadian quantum‑hardware startup Nord Quantique, explained the firm’s bosonic‑code strategy in an interview with Yuval Boger. Nord uses microwave photons confined in superconducting cavities to encode logical qubits, allowing error correction within a single resonator and avoiding the massive qubit overhead typical of surface‑code schemes. The company has demonstrated Gottesman‑Kitaev‑Preskill (GKP) and Tesseract codes, reporting a quantum‑error‑correction gain that has more than doubled since 2024. Nord plans to operate a four‑qubit system later this year and targets physical error rates between 10⁻⁷ and 10⁻⁹ by 2032. The Sherbrooke ecosystem provided capital‑efficient support, while the team highlighted challenges of scaling transmon‑based architectures. They outlined roadmap for codes that could reduce redundancy and accelerate scaling.

💡 Achieving error correction in a single cavity could shrink quantum processors dramatically, accelerating the path to practical, large‑scale quantum computers.

quantumcomputingreport.com · Oct 31

IQM Verifies Full-Chip Entanglement Across 54-Qubit Emerald Superconducting Processor

IQM Quantum Computers announced that its Emerald processor achieved simultaneous Greenberger–Horne–Zeilinger (GHZ) state entanglement across all 54 transmon qubits, marking the first full‑chip multipartite entanglement on a commercially available superconducting device. The experiment used an automated scheduling compiler that weighted individual CZ‑gate fidelities against qubit idle times, applying dynamical decoupling to cut overall error rates by up to 50 %. The resulting state fidelity surpassed the 0.500 threshold, confirming genuine entanglement despite a narrow margin. Previously, users were limited to active partitions of roughly 30 qubits. The breakthrough builds on IQM’s autonomous tuning platform, which leverages NVIDIA‑based calibration agents to maintain lattice‑wide coherence. Ongoing challenges include further gate‑speed improvements and continuous calibration to suppress localized cross‑talk significantly during deep circuit execution.

💡 Demonstrating full‑chip entanglement proves that commercial quantum hardware can sustain coherence at scale, a prerequisite for practical quantum advantage.

quantumcomputingreport.com · Oct 31

TU Delft Achieves Direct Single-Atom Nuclear Magnetic Resonance via Scanning Tunneling Microscope…

Physicists at Delft University of Technology’s Kavli Institute of Nanoscience demonstrated direct nuclear magnetic resonance control of a single surface‑adsorbed atom using a scanning tunneling microscope (STM) at 0.4 K and 1.4 T. The team introduced an Electron‑Nuclear Double Resonance (ENDOR) scheme that drives the 47Ti nucleus in the 50–85 MHz range while reading out the electronic spin at GHz frequencies. This achievement shows that isolated nuclear spins can be coherently addressed without hyperfine hybridization, offering a pathway to atomic‑scale quantum memory and high‑dimensional qudits.

💡 The work proves that nuclear spins can be manipulated directly at high magnetic fields, preserving their long coherence times. This capability could enable scalable, noise‑immune quantum registers built on engineered surface lattices.