Conventional silicon-based electronics are rapidly approaching a fundamental barrier. Below about five nanometers, quantum effects make their behavior unpredictable. That’s led to research into alternative materials such as carbon nanotubes. Now, a large collaboration has taken a different material—molybdenum disulfide, or MoS₂—and used its distinctive properties to craft a transistor that has a gate size of just one nanometer.

Unfortunately, other parts of the hardware are quite a bit larger than that, and we have no way of producing these in bulk yet. But the work validates that MoS₂‘s properties can allow us to shrink electronics down below silicon’s limits.

The idea behind the work is that a property of silicon we normally view as beneficial becomes an issue once things get small enough. That property is the mobility of electrons within silicon. On the positive side, the electrons move with less resistance when we want them to, but they also move more readily when we don’t want them to. This unwanted movement causes an increase in current leaking across transistors when they’re supposed to be off. Once silicon features get small enough (that 5nm limit mentioned above), leakage becomes large enough that it’s impossible to tell whether a transistor is on or off.