Physicists predict that the conventional silicon chip has no longer than four years left before it hits the physical limitations of the material. Alternatives such as carbon nanotubes are being investigated but scientists have been unable to build precise circuit patterns with nanotubes, limiting the application of the technology. Also superconductors could be a key to future computing, as they may be able to harness the power of quantum physics to boost computer power tremendously.

One team of researchers at the Leeds University in the UK have proposed to replace silicon chips with carbon nanotubes, which are electrically-conducive tubes of pure carbon that are tens of times thinner than a human hair. Already, some elements of computer circuits such as transistors have been constructed from individual carbon nanotubes. However, scientists have been as yet unable to precisely arrange nanotubes into circuit patterns, which is necessary to determine how each tube conducts electricity. In a development that is expected to bring carbon nanotubes one step closer to commercial use, the Leeds University researchers have developed a technique of growing nanotubes on a perforated ceramic grid. The technique allows the research team to determine the electrical propesrties of individual nanotubes, after which the tubes are accurately positioned on a surface using a tweezer-like device.

Meanwhile, other groups of scientists claim that superconductors are key to future computing, as they may be able to harness the power of quantum physics to boost computer power tremendously. Superconductors are materials that conduct electricity with zero electrical resistance, which effectively means that an electric current can circulate around a superconducting loop for an indefinite period of time. By linking the electric current in a loop to a quantum superposition state, superconductors may act as quantum bits, or qubits, in quantum computing. Qubits are able to exist in multiple states at any one time, which massively increases the amount of information that can be encoded in a quantum computer's memory. According to physicist Hans Mooij, one of the biggest challenges in making quantum computers this way is to progress from two to three qubits that communicate with each other.