Tag archives: superconductivity
By Hamish Johnston in Waterloo, Canada
Harvard’s Subir Sachdev has just taken the audience here at the Convergence conference on a delightful romp through the phase diagram of the cuprate high-temperature superconductors. What I found most interesting was not the superconducting phase, but rather Sachdev’s description of the “strange metal” phase.
This phase occurs when the cuprate copper-oxide layer is highly doped with holes and has perplexed physicists for some time – hence its strange moniker. It has no quasiparticles and lots of low-energy excitations so there is no easy way to describe the collective behaviour of the electrons.
By Hamish Johnston
High-temperature (high-Tc) superconductivity has given hope and heartbreak in equal measure to physicists since the phenomenon was first discovered in 1986.
The hope is two-fold: that we will soon understand why superconductivity arises in this complex group of materials; and that this knowledge will lead us to a material that is a superconductor at room temperature. The former would be a triumph of the physics of highly correlated systems and the latter would spark a technological revolution.
By Hamish Johnston
“How we created spooky experimental music in a superconductor lab”: what physicist could resist clicking on this story, which appeared on the Guardian website earlier this week? Written by the physicist-turned-computational-biologist Andrew Steele, the article describes how Steele and a few pals converted a magnetic sensor into a musical instrument. Like the theremin, which is played by waving your hands around an antenna, this new instrument responds to the player’s motion. But because the sensor was optimized for studying superconductors rather than creating freaky mood music, Steele explains the “instrument covered three octaves in less than a centimetre of hand movement”. He suggests that playing the instrument should probably be left to a talented gerbil rather than talented superconductor researchers. You can listen to Steele’s attempt at making music on SoundCloud.
By Tushna Commissariat at the APS March Meeting in Denver
It has been another exceedingly busy day the APS March Meeting – there were sessions on the SQUID’s many applications, robotic clams, global health physics and the spread of epidemics, and even some toys based on physics principles. Here’s another quick round-up of the fascinating talks.
On SQUID row
It’s the 50th birthday of the superconducting quantum interference device or SQUID – a very sensitive magnetometer that accurately measures extremely subtle magnetic fields – this year, and there were sessions this morning to discuss its impact to date as well as possible future applications. Kent Irwin from Stanford University discussed how superconducting photon detectors that are used in a host of astronomical and cosmological observations are being amplified using SQUIDs. Such SQUID-boosted sensors are being used to make more accurate measurements of the cosmic microwave background (CMB) – to look at its power as well as certain polarizations modes it exhibits. As certain experiments look for signs of gravitational waves in in the CMB polarization, this could be particularly helpful.