| Qubits |
Articles about Qubit |
Information AboutQubits |
| CATEGORIES ABOUT QUBIT | |
| units of information | |
| quantum information science | |
A qubit is not to be confused with a Cubit , which is an ancient measure of length. A quantum bit, or '''qubit''' (sometimes ''qbit'') is a unit of Quantum Information . That information is described by a State Vector in a Two-level Quantum Mechanical System which is formally equivalent to a two-dimensional Vector Space over the Complex Number s. Benjamin Schumacher discovered a way of interpreting quantum states as information. He came up with a way of compressing the information in a state, and storing the information on a smaller number of states. This is now known as Schumacher compression. In the acknowledgments of his paper (Phys. Rev. A 51, 2738), Schumacher states that the term qubit was invented in jest, during his conversations with Bill Wootters . BIT VERSUS QUBIT A Bit is the base of computer information. Regardless of its physical representation, it is always read as either a 0 or a 1. An analogy to this is a light switch - the down position can represent 0 (normally equated to ''off'') and the up position can represent 1 (normally equated to ''on''). A qubit has some similarities to a classical bit, but is overall very different. Like a bit, a qubit can have only two possible values - normally a 0 or a 1. The difference is that whereas a bit ''must'' be either 0 or 1, a qubit can be 0, 1, or a Superposition of both. REPRESENTATION The states a qubit may be measured in are known as Basis states (or Vector s). As is the tradition with any sort of Quantum States , Dirac, or Bra-ket Notation is used to represent them. | ||
| A | "http://wwwinformationdelightinfo/information/entry/pure_qubit_state" class="copylinks">Pure Qubit State is a linear Superposition of those two states This means that the qubit can be represented as a linear combination of <math>0
angle </math> and <math>1
angle</math>: |
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| : <math> \psi Angle | \alpha 0
angle + \beta 1
angle,\,</math> |
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| : <math> \alpha ^2 + \beta ^2 | 1 \,</math> |
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