Computers have become an indispensable part of our daily routine and our lives in general. This is why if there’s one thing we can all agree on, it’s probably that we want our computers to run faster.
How fast our devices run depend largely on their specs and the way we operate them. But in spite of how impressive the specs of our computers are, there’s always a limit to what they can do. And undoubtedly, we’re close to the tail end or the maximum theoretical limit of what silicon-based computers can do. If we want better speeds, we need to develop new technologies.
According to a paper that has recently been published in the journal Nature Photonics, a research team that includes University of Michigan engineers are a step closer towards that direction. The technology is referred to as ‘lightwave electronics’ and it can potentially lead to computers that can operate 100,000 times faster than the traditional computers we have today. Essentially, it’s the kind of technology that can help bring quantum computers closer to reality.
To be clear, the researchers are not saying that the advent of ‘lightwave electronics’ is already here. But by being able to control electron movement through laser light manipulation, they’ve shown that they have made clear progress towards it.
In traditional computers, electrons moving through a semiconductor sometimes bump into each other, releasing heat energy. In lightwave electronics, electrons can supposedly be guided by ultrafast laser pulses so that their chances of bumping into each other are effectively minimized. Comparing it with a car — driving at high speed makes the driver more prone to crashing. With electrons, moving at high speed make them less likely to hit anything.
This is what the team was able to demonstrate. They used gallium selenide for their semiconductor crystal, then shone laser pulses that lasted for less than 100 femtoseconds (or 100 quadrillionths of a second) into it.
Every time a pulse was emitted, the energy level of electrons increased and they were able to move freely. Then by altering the laser’s orientation relative to the crystal, the team was able to control the direction of the electrons’ movement.
After the electrons came down from their excited state, they emitted light in pulses that were even shorter than the terahertz radiation that went in. It is these femtoseconds-long bursts of light that show where the electrons moved. It is also these pulses that can be used to read and write information from one electron to another. In other words, these femtosecond pulses can potentially be used for quantum computing by using the ‘excited’ electrons as qubits (short for quantum bits). In contrast with regular data bits that can only take the form of 1 or 0, qubits can take the form of 1, 0, or 1 and 0 at the same time through superpositioning.
As Mackillo Kira (one of the researchers) explained in a statement: “This genuine quantum effect could be seen in the femtosecond pulses as new, controllable, oscillation frequencies and directions. This is of course fundamental physics. With the same ideas you might optimize chemical reactions. You might get new ways of storing information or transmitting information securely through quantum cryptography.”