If I told you that you could be in many different places at once, you would probably laugh aloud and promptly deem me insane. As preposterous as the idea sounds, it is possible in the world of quantum physics.
The field of quantum physics rests on the fact that everything, from energy to momentum, is quantized. Moreover, these properties can occupy many different states at the same time through a phenomenon known as superposition. This idea is can be compared to occupying many different places at once, which is counterintuitive. With this unique property, possibilities abound. Currently, scientists everywhere are attempting to harness the power of quantum physics by applying it to computer science, giving rise to a new field called quantum computing.
Just as in classical computers, information in quantum computers is stored in bits called quantum bits or “qubits.” However, unlike a classical bit, which can assume a value of either 0 or 1, a qubit can take on the values of 0 and 1 simultaneously, due to superposition. This allows a quantum computer to execute many different operations at once at an exponential rate, a previously impossible feat. The potential computing power of a quantum computer would allow it to handle very large databases and operate on similarly large numbers.
However, there are a few major challenges that are preventing the implementation of quantum computing in our daily lives. Qubits are very sensitive to external forces and will lose their state through a process called decoherence. When qubits decohere, they will settle into a 0 or 1 and lose its state of superposition, precluding the computer from reading its value. Thus, scientists are still searching for a way to effectively isolate the qubits for increased value retention time, also known as “quantum memory” time. Some recent advances in solid-state electronics have indicated that impurities in diamond could potentially be the answer.
Recent advances in solid-state electronics have indicated that impurities in diamond could potentially be the answer.
Since diamonds consist of a lattice of carbon atoms, an impurity or “defect” is when one of the carbon atoms is replaced one of another element. Nitrogen defects in diamond, where there is a nitrogen atom in place of a carbon, were first detected in 1997 by a research team in Germany led by Jorg Wrachtrup. This discovery piqued worldwide interest in diamond impurities and its applications to quantum communication, which has been gaining popularity over the years. Recently, a team from the University of Vienna (TU Wien) led by Stefan Putz, who is now at Princeton, has found that changing a few nitrogen atoms in the synthetic diamond with microwaves can increase the lifetime of the quantum state. This new improvement on qubit data storage has increased the quantum memory time to the order of microseconds. Although this is not yet long enough for daily use, it allows for computations that can be performed within nanoseconds.
The creation of a functional quantum computer would have massive implications for cybersecurity and cryptography, since secret messages could then be decoded easily with the computer’s unprecedented computing power. It would also enable the computational modelling of quantum systems, which would be groundbreaking, since it would allow scientists to study the nanoscale behavior of matter and would revolutionize the fields of physics, chemistry, and biology.