Research News

If you’re designing a new computer, you want it to solve problems as fast as possible. Just how fast is possible is an open question when it comes to quantum computers, but JQI physicists have narrowed the theoretical limits for where that “speed limit” is. The work implies that quantum processors will work more slowly than some research has suggested. 

The word “defect” doesn’t usually have a good connotation--often indicating failure. But for physicists, one common defect known as a nitrogen-vacancy center (NV center) has applications in both quantum information processing and ultra-sensitive magnetometry, the measurement of exceedingly faint magnetic fields. In an experiment, recently published in Science, JQI Fellow Vladimir Manucharyan and colleagues at Harvard University used NV centers in diamond to sense the properties of magnetic field noise tens of nanometers away from the silver samples.

JQI researchers, under the direction of Christopher Monroe have demonstrated modular entanglement between two atomic systems, separated by one meter. Here, photons are the long distance information carriers entangling multiple qubit modules.

Measuring faint magnetic fields is a trillion-dollar business.  Gigabytes of data, stored and quickly retrieved from chips the size of a coin, are at the heart of consumer electronics.   Even higher data densities can be achieved by enhancing magnetic detection sensitivity---perhaps down to nano-tesla levels.