The scientists achieved this by lowering the temperature to minus 451 degrees Fahrenheit (approx. -268°C).
At room temperature, the IBM-Georgia Tech chip operates at 350GHz, or 350 billion cycles per second. That's far faster than standard PC processors today, which range from 3.8GHz to 1.8GHz. But SiGe chips can gain additional performance in colder temperatures.More info at CNET.
To that end, IBM and Georgia Tech scientists turned down the temperature and cryogenically froze the chip at minus 451 F. It's about as cold as things get. An extremely cold temperature like that is found naturally only in outer space, but can be artificially achieved on Earth using ultracold materials such as liquid helium. Absolute zero comes at minus 459 F.
SiGe chips, the scientists theorized, could eventually hit 1 terahertz, or 1 trillion cycles a second.