Qubit States & Form Factors

Classical computer processes some definite input state according to its program to produce the corresponding output. But the input state of a quantum computer could be a superposition of many different classical inputs and consequently the quantum computer would process this state to produce a superposition of outputs.

In Quantum computer, the qubits must maintain a coherent superposition of states and this superposition must be maintained throughout the calculation, producing massive parallelism on many numbers in one execution. Once the calculation has finished, the answer must be obtained. The series of measurements gives their probability distribution from which the desired answer can be calculated.

The atoms to be quantum superposition of each other can increase the number of states.

As quantum computers use atoms or subatomic particles as qubits in order to represent bits of information. The nucleus of an atom can act like a tiny magnet, and depending on which way its magnetic field is oriented, it represents a I or a 0.

Energy from the environment can disturb the qubits, causing them to decohere. The longer a qubit remains coherent, the more operations a quantum computer can carry out.

So, there are two form factors of Quantum effecting the quantum information processing, time coherence and processing speed. They are Nuclei State Quantum Bit and the other one is Electronic State Quantum Bit.

Form factors (accounting for the qubit structure), and calculate times of coherence. It is found that the nuclei states last longer than their electronic counterpart. Which means Nuclei State Quantum Bit is more stable than Electronic State Quantum Bit.  However, this stability of nuclei qubits limits the speed at which the computer can carry out instructions and process the information. Electronic State Quantum Bit carries out instruction processing faster than Nuclei State Quantum Bit.

Computation Involve in Quantum Computing

When we talk about classical computers and computing we also talk about bits, logic gates, different registers, integrated circuits, microprocessors and computational algorithm. The same is in Quantum computing where Quantum Bit, Quantum Gates, Quantum Registers, Quantum Circuits, Quantum Bit Simulators and Quantum Algorithms are present.

When it comes to quantum computing it is said that “a process that incorporates interacting physical systems that represent qubits and quantum gates.” The Qubit is described as a vector in a two dimensional Hilbert space that hold quantum information and Quantum Register is comprises of number of qubit as a vector in multidimensional Hilbert space. Quantum gates are Hilbert space operators that rotate the qubit or quantum register vectors to change their state. Quantum Computer Simulator based on the circuit model of quantum computation. In this model quantum computations and quantum algorithms are represented by circuits, which comprise quantum gates and quantum registers.

Quantum computations are modeled and described using a circuit model. In the circuit model of quantum computation the input is the initial state of the qubits that form a quantum register and the computation is broken down in successive steps in which quantum gates act on the state of the quantum register.  The output of the circuit, i.e. the result of the computation, is the probability of measuring each one of the possible quantum register basis states and the phase of each state at each computation step. So, a sequence of computation steps is executed and at the end the final state of the quantum register, which is the computation result, is measured. 

From Classical to Quantum Computing

With the invention of the computers, it was possible to do information processing outside the brains of the humans. The architecture of computers has seen a major face-lift by undergoing a transition from vacuum tubes, transistors to today’s ultra-fast supercomputers. This has resulted in smaller faster and cost-effective computing machines. Thousands of logic gates and other digital circuits are squeezed onto the surface of a small silicon chip.

The size of microchip components will be on the scale of molecules and atoms such that quantum physical effects will dominate, hence irrevocably require effective means of quantum computation. It is known that quantum computing based on quantum physics can simulate classical computing.

The advancement in technology has now led to the design of a radically new computer architecture based on the quantum properties of an atom. This has led to the consideration of a non-Boolean approach toward computing based on the complex states of quantum matter. The advantages obtained by considering the computations at the atom level are much more than the contemporaries.

Quantum computing is a potential solution to this problem. This paradigm of computing seeks to directly exploit quantum mechanical phenomena to perform calculations or in some way boost computational efficiency. Some problems can theoretically be solved on a quantum computer exponentially faster than on a classical computer because it supports parallelism unlike classical computer. The concept of parallelism is the key major difference between Quantum computing and classical computing.

There is a quantum analogue to the bit, the qubit. The qubit is represented mathematically as a two-dimensional vector. Unlike its classical counterpart, the qubit is not limited to only two values. In fact, it can occupy an infinity of states between “0” and “1”. The quantum “0” and “1” states are represented as vector and the state of any qubit will be some superposition of these two basis vectors. State after superposition will be between 0 and 1.
The new architecture based on the quantum properties of atom will be smaller in size and much faster in speed.