Tungsten Diselenide Nano-sheet Speed Up The Quantum Computing

Current operating computers and electronics are based on motion and energy states, with an operating speed of approximately 1 billion operations per second.  Typically, the rate at which these devices apply voltage depends on the number of transistors. The smaller the switch, the higher the clock frequency and the higher the performance of the computing system. But do you know that in the future, quantum computing will increase the existing limit speed by another 1 million times and achieve 1000 trillion operations per second.

This is not bragging or delusion. Recently, a team of international physicists composed of the United States and Germany has proposed a new quantum computing method, light wave computing. This new concept is expected to control the movement of electrons more quickly, thus breaking through Moore's Law again. Most importantly, researchers believe that this technology will make quantum computing more likely than ever.

During the course of the study, scientists demonstrated how infrared laser pulses can convert electrons between two different states (typically 1 and 0) in a thin-film semiconductor. Lightwave computing technology will enable them to control the current flowing through a conventional transistor network by a factor of a million.  Of course, the focus of the breakthrough in the research is that they use a single layer of tungsten and selenium composite materials in a honeycomb lattice, that is, a single layer of nano-sized tungsten diselenide (t-selenide nano-sheet).

Quantum Computing Image

The main tructure of tungsten diselenide (WSe2)consists of a layer of selenium atoms connected to the middle layer of tungsten atoms. The adjacent two WSe2 layers have a weak van der Waals force. This material is the same as a single layer of tungsten disulfide. Extensive attention and research (graphene is almost impossible to complete this application because it is a zero bandgap material).  In the calculation of light waves, the nano-teledium selenide structure produces a pair of electronic states called spins. Like the spin quantum numbers in quantum electrodynamics (upper and lower), this is not the spin of electrons (even so, physicists warn that electrons are not actually rotating), it is an angular momentum, where two spins can encode 1 and 0.

There are only two orbits around the tungsten-selenium lattice for the excited electrons to enter.  When the crystal lattice is illuminated by infrared rays in the same direction, the electrons will jump to the first track.  When it is illuminated by infrared rays in different directions, the electrons will jump to another track.  In theory, a computer can treat these tracks as 1 and 0. When there is an electron on track 1, it is 1. When it is on track 0, it is 0.

The use of fast infrared pulses to introduce electrons into these states lasts only a few femtoseconds (thousandths of a second).  The initial pulse has its own spin, called circular polarization, that sends electrons to a  spin state.  Then, a light pulse without spin (linear polarization) can push electrons from one spin to the other - and then back.

By treating these states as ordinary 1s and 0s, it is possible to create a new type of "lightwave" computer because electrons stay in orbit for a short time, but once they enter the orbit, additional light pulses will make them  Hit back and forth between the two tracks before you have a chance to return to the non-excited state.  

The researchers pointed out that with nano-tungsten tungsten material, this 1-0-1-0 back and forth collision is much faster than current chips, and its speed is at least a million times faster than the current strongest processing chip clock speed.

In addition, electrons can also form a superposition between two chirped spins.  For a series of pulses, it should be possible to calculate until the electrons are out of their coherent state.  The team showed that they can quickly flip a qubit to perform a series of operations - basically, this speed is enough to work in a quantum processor.

The next step in quantum computing will be to acquire two qubits simultaneously, close to each other to interact with each other. For example, this may involve stacking flat semiconductor wafers or using nanostructure techniques to isolate qubits within a single wafer.

 

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