Evolution in Quantum Computing

Abstract:With the skyrocketing needs of rapid processing speed and miniaturization, classical computers are not able to keep up the pace with these few necessary parameters. As classical computers work on classical mechanics there expansion is at zenith. Due to these limitation quantum mechanics is taking the role of game changer in race of computation. Quantum computing studies quantum computer with the quantum mechanics phenomenon of superposition, entanglement, tunneling and annealing to solve problems that can’t be solved in life span of human beings. This review aims for summarizing timeline of the quantum computing along with quantum mechanics behind it.

Published in: 2016 International Conference System Modeling & Advancement in Research Trends (SMART)

A Role for IEEE in Quantum Computing

Erik P. DeBenedictis, Sandia National Laboratories


Will quantum computation become an
important milestone in human progress?
Passionate advocates and equally passionate
skeptics abound. IEEE already provides useful,
neutral forums for state-of-the-art science
and engineering knowledge as well as practical
benchmarks for quantum computation
evaluation. But could the organization do more?



Quantum Computers

About quantum computers

Quantum computers will use two fundamental properties of the quantum world: superposition and entanglement.
So, what is superposition? Qubits can be in the “|0⟩” state (called a zero-ket), the “|1⟩” state (called the one-ket), or a linear combination of the two (superposition). The half-angle bracket notation |⟩ is conventionally used to indicate qubits, as opposed to ordinary bits. When you measure the |0⟩ quantum state, you get a classical 0, and when you measure the |1⟩ quantum state, you get a classical 1. The |0⟩ state is sometimes called the ground state because in many physical implementations of quantum computing, including mine, it is the lowest energy state.

What’s a QBit ?

A qubit is a quantum system consisting of two energy levels, labeled |0⟩ and |1⟩. The |0⟩ state is often called the ground state because it is the lower of the two energies. Together, |0⟩ and |1⟩ make up what we call “standard basis vectors”. Like all vectors, they point in a direction and have a magnitude. Defining basis vectors is a really useful trick we have borrowed from linear algebra. The basic idea is that once you have defined these vectors, you can construct any other vector from a linear combination of the basis vectors.
Additionally, qubits also have a “phase”, which results from the fact that superpositions can be complex. To represent these superpositions, we put a coefficient such as a or b in front of the state like so: a|0⟩+b|1⟩. Here’s what the formula is saying: “The state is made up of a linear combination of |0⟩ and |1⟩, where the proportion of each depends on the coefficients a and b.” The coefficients a and b could be positive, negative, or even complex. If we take the absolute value of a or b and square it (e.g. |a|2‘or:math:‘|b|2 ), we get the probability of measuring the 0 or 1 outcome, respectively.
The basis states |0⟩ and |1⟩ and their linear combinations a|0⟩ + b|1⟩ describe the state of a single qubit. But because the coefficients a and b are not just real numbers, but can be imaginary or even complex, visualizing a qubit requires a special tool called the Bloch Sphere. The Bloch Sphere is a sphere with a radius of one and a point on its surface represents the state of a qubit. Like a globe uses longitude and latitude to describe points on the surface, the Bloch sphere can also use angles to describe the state of a qubit. This representation allows any qubit state, including those with complex coefficients, to be represented as a point on the surface of the Bloch sphere. Points on the surface of the Bloch sphere which lie along the X, Y, or Z axis correspond to special states as described below.