Does coming first mean gold?

China will be very much in focus as we are about to be inundated by 24/7 media coverage -- the BBC is supposedly taking 470 people -- of the Olympic games less than a few days away in Beijing. But as the recent furore over the Chinese authorities restricting internet access for journalists escalated and then retreated, one thing is for sure: reporters may be writing about China's many gold medals at the events, but it may be in Research and Development (R&D) where China will be more satisfied about surpassing the US.

When I was a PhD student -- seemingly a long time ago -- at the Max Planck Institute (MPI) in Stuttgart, many of the seven main departments were brimming with Chinese researchers. At one point, the group meetings seemed to contain more Chinese scientists than German. Indeed, the MPI's are quite international centers for research, which are are geared around cutting edge facilities, high levels of funding and under the provision that no-one is required to do any teaching. Perfect places to quickly increase your knowledge of a myriad of experimental techniques and practices.

When I asked most of the Chinese researchers, who usually stayed on average around 2 years at the MPI, were they would be going next. Rather than saying going to the US or even staying in the research intensive environment of the MPI, most said they are going back to China, even some armed with government incentives such as a rent free house or a car.

But if this was a real government initiative to pull some of the researchers back from going abroad, it seems to be working. Productivity -- loosely defined as the number of papers with at least on researcher based or with formal affiliation to China -- has rocketed in the past few years. In physics more than 22 000 papers were published with one Chinese author, a five-fold increase from 2000. This figure has already surpassed the UK, France and Germany, and on the current trend will overtake the US in 2012 -- or in time for the next Olympics if you like.

Some research areas that I looked into for a recent article in this month's PhysicsWorld showed that China was racing ahead in nanoscience, publishing almost 13 000 articles in 2007, quantum information and high temperature superconductivity. Indeed, recently in the case of the latter, this rise has been most obvious. Ever since Japanese researchers found superconductivity at 26 K in an iron-based material in March, Chinese researchers have been at the forefront experimentally, having many of the breakthroughs themselves, such as increasing the transition temperature -- the temperature at which the material loses its electrical resistance -- to 55 K.

But the rise in quantity is not a loss in quality. The number of Chinese researchers publishing in Physical Review Letters, Nature and Science has also been increasing in the last few years. Particularly in Nature it has exploded, almost a ten fold increase from around 10 articles per year in the 1990's to 111 in 2007 -- though this may, or may not, reflect the tendency for Nature to publish a good fair share of papers in nanoscience.

But with China aiming to increase its spending on R&D from 1.4 % to 2.5 % in 2020, its not only going to be quick off the starting blocks, but seems to be in for the long distance.

Resistance is futile

If you mentioned to people what they remember about 1986, what would they say? You may get answers such as the challenger space shuttle disaster which killed all seven crew; Argentina winning the World cup with the help of Diego Maradona or maybe the year when the European flag was adopted by the European Union. Probably one answer you wouldn't get (unless you happened to ask a physicist) is the discovery of high temperature superconductivity.

Superconductivity is one of those weird effects in nature: if you cool a metal such as lead or tin to low temperatures then all of a sudden its resistance will fall to zero, meaning that below this temperature, a current flowing through a wire of this material will incur no resistance and therefore persist indefinitely.

The discovery by Bednorz and Müller of superconductivity at 30 K was important for a number of reasons, one was that the standard model of superconductivity didn't allow superconducting transition temperatures this high (lead and tin are 7 and 4 K respectively) thus leading to a potential new mechanism for superconductivity. Two, it opened up a variety of related materials which pumped up the superconducting transition to 138 K at standard pressure in 1995 (applying an external pressure makes it go even higher). The discovery was so important that even by the next year Bednorz and Müller were awarded the Nobel prize in physics.

These materials, known collectively as the cuprates, are a double edged sword. One they enable very high superconducting transition temperatures to be achieved by chemical substitution and/or doping, but this delicate parameter space has meant getting a coherent experimental and theoretical picture of high temperature superconductivity has become cloudy.

A few years after the discovery, there were around 8000 papers per year being churned out, that fell to around 5000 in 2005 (still a high number nonetheless). Indeed, someone new to the field has to either spend a decade reading every publish paper or only select papers in the top journals. Grants were being pulled on research in high temperature superconductivity, researchers were thinking about other topics, a theory, and new materials seemed elusive.

but maybe that's about to change..

At the end of February a group of researchers in Tokyo reported a new Iron based superconductor at 26 K. Now, 26 K is still far less than the record, but already a few theoretical papers came out predicting that this was not a standard 'low' temperature superconductor - another high temperature superconductor has hit the scene.

Not only did it take a few days later before the first experimental paper on arxiv came out, by today there has already been around 20 papers on this material on arxiv. With chemical substitution the superconducting transition temperature has already increased to 52 K in a related material.

Are there similarities between the cuprates? Probably in more sense that one. The ability to substitute elements and also to tweak the amount of oxygen or other halogens means the parameter space is large. The 'first to the finish line' approach in superconductivity research in terms of finding a new superconductor with an even higher superconducting transition temperature is likely to make a splurge of papers to come out shortly.

Maybe this material gives us a chance to find out the mechanism for high temperature superconductivity or puts the elusive room temperature superconductor in sight. An explanation will need experimentalists to produce careful measurements that give theorists a clear view.