Computers running 100,000 times faster than modern computers can radically change our lives. They could help to quickly identify remote planets or much earlier diagnose a disease in a patient, and much more. A group of researchers, which included engineers from the University of Michigan, believe that they have found a way to achieve this goal with the help of ultrashort laser pulses. Researchers have developed and demonstrated a method for controlling light pulses of duration in femtoseconds, that is quadrillionths of a second, which allows to move electrons faster and more efficiently. The University of Michigan states that this is a step towards “light-wave” electronics, and ultimately, quantum computing.
In modern computers, some of the electrons passing through semiconductors collide with each other and release energy in the form of heat. This is not a very effective technology. The researchers used gallium selenide crystals as semiconductors and sent short laser pulses to them. These pulses moved electrons from one energy level to another, higher. When electrons return back from higher energy levels, they emit even shorter pulses.
These extremely short pulses can be used to quickly read and write information with the help of electrons, but in order for this possibility to appear it is necessary to gain control over these impulses. A group of scientists discovered that changing the orientation of the crystals allows them to control the direction of motion of electrons and their character of their displacements. The University of Michigan explains that “since the femtosecond pulses are short enough to intercept the electron between transition to the excited state and return from this state, they can potentially be used for quantum computations using electrons in the excited state as q-bits, or quantum bits.
Despite the fact that much work remains to be done before this method can be used in working lightwave or quantum computers, it represents a big step towards the goal. Leading researcher Professor of Physics from the University of Regensburg, Rupert Huber said: “Over the past few years, we and other groups have discovered that the oscillating electromagnetic field of ultrashort laser pulses can actually move electrons in solids forward and backward. Everything was immediately inspired, because this principle can be used to build future computers that would work at unprecedented high clock speeds, 10 to 100 thousand times higher than the most advanced samples of modern electronics. “