Quantum mechanics is strange. When its ideas are harnessed properly however, it can lead to some mind boggling changes in the technology available to humankind. The most promising of such applications is in the field of computing. Quantum computer is an information processing system that can operate utilizing two bizarre quantum properties – quantum superposition and quantum entanglement. A classical computer or digital computer as we call it, operates on the basis of binary digits or bits (0 and 1), whereas a quantum computer uses what is called a ‘qubit’ which can exist as a mixed state of 0 or 1. This apparently simple difference causes a quantum computer to operate at an exponentially faster speed compared to a classical computer. To put it in perspective, it has been posited that a problem which classical computers would take billions of years to solve, can be solved by a quantum computer in a matter of hours. Having said that, a fully functioning practical quantum computer is years, most likely decades away. There are several key problems which need to be tackled. Existing quantum processors contain only a few tens of qubits where a practical quantum computer need millions of qubits to function as a versatile problem solver. These existing systems only function at extremely low temperature (around 4 K or -2690 C) which is very difficult to maintain and the qubits suffer from decoherence (loss of superposition state). Decoherence has been dubbed as the biggest obstacle for quantum computing. Researchers are working with many types of particles and systems as potential qubits. Recently, the discovery of room temperature quantum emitters or single photon emitters as naturally occurring defects in some materials (Hexagonal Boron Nitride, TMD) have opened up a new possibility. These solid state quantum emitters have exceptionally high coherence time which makes them a potential candidate as qubits. The next step is to devise a way to manipulate and control the coherence of these emitters and limit their interaction with the surrounding environment as temperature rises. Succeeding in these steps have the possibility to pave the way for a practical quantum computer.
