Diamonds Could Be a Patient's Best Friend Too

Quantum computers are currently one of the largest objectives for the electronics industry. They will be able to calculate immensely complicated codes faster and more accurately than the current technology can, as they will make use of the quantic principle of superposition. This principle dictates that a quantum bit, or qubit, can exist in two states at the same time. But, before the idea yields practical results in computing, experts at the National Institute of Standards and Technology (NIST), led by theoretical physicist Jacob Taylor, say that it may have immediate applications in medicine.

The expert discovered that qubits had a great sensitivity to magnetic fields, which means that Magnetic Resonance Imaging (MRI)-like probes that can analyze the properties of individual drug molecules or living cells may soon become possible. The most likely system to be able to do that is made up of a nitrogen atom lodged within a diamond crystal, as it can sense atomic-scale variations in magnetism. Additionally, the structure functions at the room temperature, which means that no special conditions are required for its normal operation.

As everyone knows, diamonds are the purest form of carbon in existence. Created at high temperatures and pressures, the compound features neatly ordered carbon atoms, which clump together in a crystalline lattice. However, small impurities known as “nitrogen vacancies” exist. This means that, inside the diamond, two of the carbon atoms have been replaced at some point by a single nitrogen atom. In fact, it's these vacancies that give the stones their famous luster, experts say.

When green light strikes them, these impurities are what makes the precious stone fluorescence. Nitrogen atoms have two excitable, unpaired electrons that glow a brilliant red under green light. Slight variations in this fluorescence can be used to calculate the magnetic spin of a single electron in the nitrogen atoms. By continuously transmitting information between the nitrogen electron and the nuclei of adjacent carbon atoms, the NIST team essentially created a small circuit, capable of logic operations. The spin of the electrons is characterized by “up” or “down,” similar to a computer bits' “1” and “0” states.

Taylor also discovered that, by repeatedly sending the information back and forth, the signal could be amplified to a point where it became easy to read. Picking up such signals in a quantum processor has thus far proven to be a daunting and insurmountable task. The expert believes that the field of medicine may rip the benefits of this find faster than the first, true quantum processor, as the discovery is “evolutionary, not revolutionary.” Diamond-tipped sensors, Taylor believes, could potentially be used to test individual cells inside the body, or maybe even single molecules in drugs pharmaceutical companies are working on.

“That's commonly thought not to be possible because in both of these cases the magnetic fields are so small. But this technique has very low toxicity and can be done at room temperature. It could potentially look inside a single cell and allow us to visualize what's happening in different spots,” he said. Details of the investigation were published online in the September 10th issue of the top journal Science. Scientists from the Joint Quantum Institute, the Massachusetts Institute of Technology (MIT), and the Texas A&M University also participated in the investigations.