Calculating the Unknown

​​The race is on for a practical quantum computer, with companies like Google, IBM, and, most recently, Honeywell vying for the lead. Another leader is the collaborative effort between computer chip maker Intel and QuTech, an offshoot of Delft Technical University’s Kavli Institute of Nanoscience. They recently announced that they had developed an integrated circuit that combines—for the first time—both qubits (units of quantum energy) and the electronic controls needed to manage those qubits. In other news, we look at a device that knows exactly how anxious you are, and software that works by mathematically mapping relationships between materials.

Quantum control

Researchers have achieved a major milestone on the road to large-scale quantum computer: an integrated circuit that can control up to 128 qubits at temperatures close to absolute zero. This will make it possible to build integrated circuits that incorporate both qubits and the circuitry needed to make them work, which is pretty much how all electronic processors work today. Until now, however, qubits have been individually wired to control electronics because the controllers, which give them their commands and make measurements to determine answers, could not operate at such low temperatures. The work was done by a research team from Intel and QuTech, a quantum computing center founded by Delft Technical University. Many members of Delft’s Kavli Institute of Nanoscience are also members of QuTech, including Lieven Vandersypen, who was part of the controller research team.

Calculating the unknown

For decades, materials scientists have dreamed about using computers to discover new materials or calculate the unknown properties of existing ones. Now, a new open-source software package, propnet is doing just that. The package was pioneered by Kristen Persson, a member of the Kavli Energy and NanoScience Institute at Berkeley. The software works by mathematically mapping relationships between materials. For example, they started with a material called wurtzite CdTe, a combination of boron nitride and cadmium telluride, the second most widely used solar cell material in the world. Persson's team inputted 20 values for 20 properties, propnet calculated 629 distinct new values for 41 unknown properties. The software can also help researchers who need specific electrical, physical, or optical properties zero in on exactly the type of material they should be testing.

Don’t sweat the anxiety

By now, everyone is familiar with wearables that collect health data like activity, heart rate, ambient noise and even blood pressure and menstrual cycles. Now, add to that cortisol, a hormone produced when people are under stress. Wei Gao, a member of the Kavli Nanoscience Institute at Caltech, has developed a low-cost sensor that is fast, accurate, and can be mass produced. It makes it by laser-etching a sheet of plastic to produce graphene that is so porous, it has enough surface area to detect the presence of cortisol in sweat. It could replace the questionnaires most medical professionals now give patients and help treat stress, anxiety, post-traumatic stress disorder, and depression. Gao built a similar sensor to sample uric acid in sweat to help control cardiovascular disease, diabetes, and kidney disease.