Home > News > What is a qbit?
April 6th, 2010
What is a qbit?
By Roy Johnson
Quantum computing is based on different mathematics and different hardware from conventional, binary computing.
Quantum computers already exist, in one form or another, and they work with qbits, not the usual 1/0 bits. A qbit is, mathematically, a state vector in a two-level quantum system or a vector that applies to complex numbers. Putting it simply and practically, a qbit can have the value 1,0 or both. In quantum language the simultaneous 1/0 value is called a superposition.
It seems impossible to use something that doesn't have a rigidly fixed and measureable value. It conjures up scary memories of the Heisenberg Uncertainty Principle and the Schrodinger's Cat problem.
In fact, we do know the maths that enable us to work with qbits - it's basically a matter of probabilities. If you think of the traditional 1/0 values as a sphere, 1 being the north pole and 0 being the south pole, the possible states of a qbit - determined by probability amplitude - will fall on the surface of that sphere.
Quantum states also have the unique property of entanglement. This is a non-local property of quantum states (qbits, for example) whereby two sets will have higher correlation than is possible in classical mathematics. Simply and somewhat inaccurately expressed, this allows quantum machines to work quickly on problems that a conventional machine can solve - but only with impossible time scales.
News and information
NanoTechnology for Defense (NT4D) October 22nd, 2014
Mechanism behind nature's sparkles revealed October 22nd, 2014
TARA Biosystems and Harris & Harris Group Form Company to Improve Safety and Efficacy of New Therapies October 22nd, 2014
Researchers patent a nanofluid that improves heat conductivity October 22nd, 2014
Imaging electric charge propagating along microbial nanowires October 20th, 2014
Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014
Nanocoatings Market By Product Is Expected To Reach USD 8.17 Billion By 2020: Grand View Research, Inc. October 15th, 2014
Perpetuus Carbon Group Receives Independent Verification of its Production Capacity for Graphenes at 140 Tonnes per Annum: Perpetuus Becomes the First Manufacturer in the Sector to Allow Third Party Audit October 7th, 2014
1980s aircraft helps quantum technology take flight October 20th, 2014
Australian teams set new records for silicon quantum computing October 12th, 2014
Ultrafast remote switching of light emission October 2nd, 2014
Quantum environmentalism: Putting a qubit's surroundings to good use October 2nd, 2014