Elementary Mr. Watson: Running the Signal Gauntlet
The Shaughnessy Report: Winning the Signal Integrity Battle
Connect the Dots: How to Avoid Five Common Causes of Board Failure
Scientists Study the Insulator-Superconductor Transition of Copper-Oxide Compound in Fine Detail
April 11, 2016 | BNLEstimated reading time: 4 minutes
At a fixed low temperature, decreasing the doping level or increasing the applied magnetic field both suppressed superconductivity, allowing a competing state of electronic order to take over. Dramatic fluctuations appeared in the Hall resistance below a critical temperature, and these fluctuations increased in frequency and magnitude as all samples were further cooled toward absolute zero, indicating that they are of quantum origin.
"The behavior of these fluctuations is opposite to that seen in fluctuations driven by thermal energy, such as the vapor bubbles that appear when water is boiled," said Wu. "The bubbles fade away as the temperature is lowered."
The Hall resistivity measurements compared over the entire range of magnetic fields tested revealed that the samples have "memory" of their prior electronic states. After a magnetic field was applied, the value and sign of the Hall resistivity changed. When the magnetic field was removed, the samples stayed in the same electronic configuration until the field was reapplied—a very unusual property for conductors.
The scientists' data reveal that, at near-absolute-zero temperatures, the superconducting state competes with another state of electronic order characterized by the random distribution of many small charge "clusters," or localized groups of electrons. Unlike the free-flowing electrons in metals and superconductors, the electrons in these clusters are localized and pinned to particular atoms, rendering them immobile and unable to carry current when an electric field is applied. The clusters can hop around and trade places in the lattice as a result of quantum fluctuations.
"This picture explains the weak conductivity of this strange "insulating" state, revealing that the state originates from localization of charges," said Wu. "Our conclusion builds upon our understanding of the insulator-superconductor transition in an important class of high-temperature superconductors. We are one step closer toward our goal of predicting and designing new superconducting materials with superior properties for energy applications."
This research was funded by the Office of Science within the U.S. Department of Energy. Other authors include Anthony Bollinger of Brookhaven Lab and Yujie Sun of Brookhaven Lab and the Chinese Academy of Sciences.
Page 2 of 2Share on:
Testimonial
"In a year when every marketing dollar mattered, I chose to keep I-Connect007 in our 2025 plan. Their commitment to high-quality, insightful content aligns with Koh Young’s values and helps readers navigate a changing industry. "
Brent Fischthal - Koh YoungSuggested Items
Trouble in Your Tank: Implementing Direct Metallization in Advanced Substrate Packaging
09/15/2025 | Michael Carano -- Column: Trouble in Your TankDirect metallization systems based on conductive graphite are gaining popularity throughout the world. The environmental and productivity gains achievable with this process are outstanding. Direct metallization reduces the costs of compliance, waste treatment, and legal issues related to chemical exposure. A graphite-based direct plate system has been devised to address these needs.
Closing the Loop on PCB Etching Waste
09/09/2025 | Shawn Stone, IECAs the PCB industry continues its push toward greener, more cost-efficient operations, Sigma Engineering’s Mecer System offers a comprehensive solution to two of the industry’s most persistent pain points: etchant consumption and rinse water waste. Designed as a modular, fully automated platform, the Mecer System regenerates spent copper etchants—both alkaline and acidic—and simultaneously recycles rinse water, transforming a traditionally linear chemical process into a closed-loop system.
Driving Innovation: Depth Routing Processes—Achieving Unparalleled Precision in Complex PCBs
09/08/2025 | Kurt Palmer -- Column: Driving InnovationIn PCB manufacturing, the demand for increasingly complex and miniaturized designs continually pushes the boundaries of traditional fabrication methods, including depth routing. Success in these applications demands not only on robust machinery but also sophisticated control functions. PCB manufacturers rely on advanced machine features and process methodologies to meet their precise depth routing goals. Here, I’ll explore some crucial functions that empower manufacturers to master complex depth routing challenges.
Trouble in Your Tank: Minimizing Small-via Defects for High-reliability PCBs
08/27/2025 | Michael Carano -- Column: Trouble in Your TankTo quote the comedian Stephen Wright, “If at first you don’t succeed, then skydiving is not for you.” That can be the battle cry when you find that only small-diameter vias are exhibiting voids. Why are small holes more prone to voids than larger vias when processed through electroless copper? There are several reasons.
The Government Circuit: Navigating New Trade Headwinds and New Partnerships
08/25/2025 | Chris Mitchell -- Column: The Government CircuitAs global trade winds continue to howl, the electronics manufacturing industry finds itself at a critical juncture. After months of warnings, the U.S. Government has implemented a broad array of tariff increases, with fresh duties hitting copper-based products, semiconductors, and imports from many nations. On the positive side, tentative trade agreements with Europe, China, Japan, and other nations are providing at least some clarity and counterbalance.