Phys.org May 10, 2022 An international team of researchers (France, Germany) built a on-chip circuit which is a simple battery-biased superconducting tunnel junction in series with a microwave resonator. At discrete values of the battery voltage, a dc current flows through the circuit, with the emission of several photons at the resonator frequency for each superconducting pair of electrons that tunnels across the junction. They measured the total microwave power emitted and characterized the granularity of the emission both of which were good agreement with a simple theoretical model. In particular, at a small transparency of the tunnel junction, they […]
Tag Archives: Quantum physics
Direct printing of nanodiamonds at the quantum level
Nanowerk May 4, 2022 The quantum defects in nanodiamonds, such as nitrogen-vacancy (NV) centers, are emerging as promising candidates for nanoscale sensing and imaging, and the controlled placement with respect to target locations is vital to their practical applications. Researchers in Hong Kong have developed on-demand electrohydrodynamic printing of nanodiamonds containing NV centers with high precision control over quantity and position. After thorough characterizations of the printing conditions, they showed that the number of printed nanodiamonds can be controlled at will, attaining the single-particle level precision. This printing approach enables positioning NV center arrays with a controlled number directly on […]
Evading the uncertainty principle in quantum physics
Phys.org May 6, 2021 Quantum mechanics sets a limit for the precision of continuous measurement of the position of an oscillator. An international team of researchers (Finland, Australia) has developed a theoretical model to show that there is a way to get around the uncertainty principle. In their experiment they used two vibrating drumheads vibrating in opposite phase to each other cancelling the quantum uncertainty of the drums’ motion if the two drums are treated as one quantum-mechanical entity. Thus the researchers were able to simultaneously measure the position and the momentum of the two drumheads – which should not […]
Engineering the boundary between 2D and 3D materials
MIT News February 26, 2021 The atomic structure at the interface between 2D and 3D materials influences properties such as contact resistance, photo-response, and high-frequency electrical performance. An international team of researchers (USA – MIT, Harvard University, Canada) used epitaxially aligned MoS2/Au as a model system to demonstrate the use of advanced scanning transmission electron microscopy combined with a geometric convolution technique in imaging the crystallographic moiré pattern at the 2D/3D interface. This moiré period is often hidden in conventional electron microscopy, where the Au structure is seen in projection. They showed that charge density is modulated according to the […]