Low Power Superconductors

CMOS transistors is the most important technology in today's semiconductor world but we are 5-10 years away achieving the excellence of computing because superconductor makes computing much more faster and less power consumption. New logic designs are emerging that suggested superconducting processes could be not only faster but power efficient. The next generation computers called exaflop computers possesses the ability to execute 10^18 operation per second and about 1000 times much faster than the classical CMOS chip that we have but research shows that it is impossible to built these computers with the sister CMOS technology since the power consumed by these exaflop CMOS chip is 500MW(you might think I am kidding or I wrote something wrong in hurry) but yeah 500MW is it that's the power generated by a nuclear plant.

Superconducting circuits have long been the attractive option for ultra fast operation cooling mercury in liquid helium close to the absolute zero makes mercury a resistance less conductor which carries current smoothly in faster way and without dissipating any power ideally it is considered that superconductor consumes 0 power. But the current technology in the market is somewhat different that the superconductor one. Most superconductor circuits 1990 since are build using the RSFQ (rapid single flux quantum logic), which relays the the bit information in the form of short voltage signal carried by the speeding vortices current. It is used in many technologies but this design too consumes large power when it is scaled up to a processor for high end computers because to distribute current around the gates it uses the bias resistance that consumes 10 times large current that the superconductor logic use for computation. To eliminate the errors some scientist switched the supply from DC to AC which replaced the resistors by the transformers that don’t draw power when circuit is not performing computation. Even though we have different technologies superconductors are absolute in it nature 10 more years and we ll witness the power of superconductors. At this moment all we can say is we are at the ground floor of the revolution.

Some thing about quantum after many days

Quantum Cryptography is one of the most finest and upcoming technique which harness all the security issues that we are facing now a days.

Inspite of having 128 bit SSL encryption cyber attacks makes system vulnerable and insecure to use.

But the quantum cryptography makes all the system secure but in other way it can exacerbate all the network channels and can break almost every RSA code in less than a second.

there are some links you can refer.

Quantum computing: Some useful linkes

http://spectrum.ieee.org/nanoclast/semiconductors/nanotechnology/graphene-demonstrates-capabilities-in-spintronics

Quantum computing: Some useful linkes

http://spectrum.ieee.org/computing/it/quantum-cryptography-cracked

Some useful linkes

Because of some problem I couldn't post new article on this blog but there are some useful links related to our main topic of quantum computing and semiconductor physics that I would like to post here.
The new discovery of the graphene transistors will make the silicon ones obsolete in these coming years, looking into some arduous tasks in quantum computing we need some interface which we can provide us ultra fast switching in logic and in some gateways.

The Graphene transistors toggles with ultra high speed of 330THz, which is 100 times faster than the fastest metal oxide semiconductor field effect transistors generally known as MOSFET. But the major problem is when we cascade these transistors to form a gate or a flip flop then the speed reduced drastically to solve this problem a nanowire architecture has been developed which you can read in these links.

And the new phenomenon that a graphene exhibits is a single curved sheet of graphene with a diameter of of few nanometer can influence a electron spin so we can manipulate these spins of subatomic particles.

Quantum States Part 2

Last time we had basic introduction about the quantum states ,This time we will study those in a brief . As we all know there are two types of quantum states PURE state and MIXED state , The pure state describes a position (spin) of a subatomic particle by a single KET vector while a mixed state is a mixture of pure states.

PURE STATE:

In last post we have seen that the basic unit of the data in fundamental computing is bit in which the maximum states can be labeled are two either 0 or 1 keeping the context same the quantum bit usually called as qubit is analogous to a bit having the capability to represent 3 states instead of two of that of bit. But note that like a bit quit can also have 2 state but that become obscure and ambiguous as we see the superposition phenomenon. Those two states are generally called as THE SPINS of subatomic particles and their notifications are |0> for negative spin and |1> for the positive spin one may ask a question whats the difference between bit and qubit as they are same with number of states (0 and 1) but there is one more state which is the most important called as SUPERPOSITION STATE . This state is the linear combination of those two state |0> and |1>.

And which is represented by ψ and the linear equation which represents the superposition state is

|ψ>=α |0> +β|1>.

Where α and β are the two complex numbers generalized as a+ib. where i^2=1.

While a qubit can exist in a superposition of 0 or 1 as I have seen in earlier post due to the property of uncertainty if we do the measurement we aren’t going to find the exact state of superposition because position and momentum of quantum particles cannot be measured simultaneously so we calculate it in the form of probability distribution .

|α^2>= Tells us the probability of finding the superposition | ψ> in 0^th state.

|β^2>= Tells us the probability of finding the superposition | ψ> in 1^st state.

Mixed State:

A mixed state is somewhat different than the pure one. It cannot be described by the ket or a vector instead of that it can be represented by a density matrix , and it is denoted by a symbol ρ we can say that it’s a generalize state equation because it can represent pure state as well as mixed and the density matrix is defined as

|In which Ps is the part of the two different superposition’s .to check whether the state is pure or mixed one should find the trace of p^2 if the trace is 1 then it is a pure state and if it is less than 1 then it is a mixed state . Note that the trace cannot be greater than 1 because we are dealing with probability distribution and it cannot be greater than 1.

Quantum States Part 1.

In the last post we had the basic introduction to quantum computing and the need of it ,But to develop quantum algorithms and logic one must have the all knowledge of the quantum states of sub atomic particles , because quantum computing is the integration of particle physics and computing (as said by Richard Feynman ) Before going to the actual states we need to understand the energy fundamentals associated with the subatomic particles (how they act so weird).
Before 19th century people used to believe that energy is continuous in nature but in 19th century MAX PLANK proved that energy always present in discreet packets called quanta . this is really important because if we think that energy is continuous we can cut it in piece of value that we want and the absoluteness of the electron or photon would had no significance and there wouldn’t be any need for studying photoelectric effect or Compton effect. In other words I would be saying ‘I want to buy 1.5 shirt or 2.74569 laptops ‘ .
PlANKS CONSTANT:
h =6.626*10^-34 j.s (note that energu is always multiplied by seconds in this constat)
but after some advance research it has found that whenever we use the planks constant in equation we divide it by 2π . It is all related to the angular motion which electronics possess .
so the new value of planks constant is h1=h/ 2π.
Which is 1.05456*10^-34.
Quantum States are basically the positions possessed by the subatomic particles at certain event ‘t’. As per the uncertainty principle its impossible to determine the position and momentum of the electron simultaneously , since the phenomenon is equivocal ,but we can define the state by putting them in a mathematical tool called as KET , KET is a collection of the no of states of subatomic particles, for an example we will take a hydrogen atom , in which I,j,k variables describes the state of the electron it may be a pure state or it may be mixed , but one important thing about these states are they always been calculated as the probability function because practically its almost impossible to locate or track the exact position of electron they may be present at two different places at same time , for example if ask you that whats the probability of you going Jupiter with no time ? you may call me insane for asking this stupid question but there is a valid number it may ->0 but still there is a probability . It may make you to think about parallel universe and STRING THEORY , MEMBERANE THEORY etc.
So the states are subdivided into two groups
1) Pure State.
2) Mixed States.
Pure states are extreme pure a positive spin ,negative spin or a superposition
While a mixed statistical state is mixture of two pure its complex and depends on probability function of two different pure states
As the states are need to explained by formulating them in actual KET we will discuss the later part in the next article .