This article is about the quantum computing unit. For other uses, see Qubit (disambiguation).
Not to be confused with Cubit.
Units of information
Information-theoretic
shannon (base 2)
nat (base e)
hartley (base 10)
Data storage
bit (binary)
trit (ternary)
dit (decimal)
Quantum information
qubit (binary)
qutrit (ternary)
qudit (d-dimensional)
v
t
e
In quantum computing, a qubit (/ˈkjuːbɪt/) or quantum bit is a basic unit of quantum information—the quantum version of the classic binary bit physically realized with a two-state device. A qubit is a two-state (or two-level) quantum-mechanical system, one of the simplest quantum systems displaying the peculiarity of quantum mechanics. Examples include the spin of the electron in which the two levels can be taken as spin up and spin down; or the polarization of a single photon in which the two spin states (left-handed and the right-handed circular polarization) can also be measured as horizontal and vertical linear polarization. In a classical system, a bit would have to be in one state or the other. However, quantum mechanics allows the qubit to be in a coherent superposition of multiple states simultaneously, a property that is fundamental to quantum mechanics and quantum computing.
In quantum computing, a qubit (/ˈkjuːbɪt/) or quantum bit is a basic unit of quantum information—the quantum version of the classic binary bit physically...
in quantum computing is the qubit, similar to the bit in traditional digital electronics. Unlike a classical bit, a qubit can exist in a superposition...
electronic circuits using superconducting qubits as artificial atoms, or quantum dots. For superconducting qubits, the two logic states are the ground state...
The Qubit fluorometer is a laboratory instrument developed and distributed by Invitrogen, which is now a part of Thermo Fisher. It is used for the quantification...
In quantum computing, a qubit is a unit of information analogous to a bit (binary digit) in classical computing, but it is affected by quantum mechanical...
specifically in superconducting quantum computing, flux qubits (also known as persistent current qubits) are micrometer sized loops of superconducting metal...
quantum gate) is a basic quantum circuit operating on a small number of qubits. Quantum logic gates are the building blocks of quantum circuits, like classical...
In quantum computing, a charge qubit (also known as Cooper-pair box) is a qubit whose basis states are charge states (i.e. states which represent the presence...
superconducting quantum computing, a transmon is a type of superconducting charge qubit designed to have reduced sensitivity to charge noise. The transmon was developed...
0.66. Three qubits are required for this process: the source qubit from the sender, the ancillary qubit, and the receiver's target qubit, which is maximally...
IBM Condor is a 1,121-qubit quantum processor created by IBM, unveiled during the IBM Quantum Summit 2023, which occurred on December 4, 2023. It is the...
stored in the logical qubit—as otherwise the measurement would destroy any quantum superposition of this logical qubit with other qubits in the quantum computer...
operate as a quantum bit, or qubit. The phase qubit is closely related, yet distinct from, the flux qubit and the charge qubit, which are also quantum bits...
the Bell's states or EPR pairs: 25 are specific quantum states of two qubits that represent the simplest examples of quantum entanglement. The Bell's...
The One Clean Qubit model of computation is performed an n {\displaystyle n} qubit system with one pure state and n − 1 {\displaystyle n-1} maximally mixed...
introduces a global phase e i φ {\displaystyle e^{i\varphi }} to the whole qubit quantum state. A quantum state is uniquely defined up to a phase. Because...
register consisting of 2 qubits. The CNOT gate flips the second qubit (the target qubit) if and only if the first qubit (the control qubit) is | 1 ⟩ {\displaystyle...
classical bits of information by only transmitting a smaller number of qubits, under the assumption of sender and receiver pre-sharing an entangled resource...
due to the different architectures and approaches. Due to this, published qubit numbers do not reflect the performance levels of the processor. This is...
the no-cloning theorem. Alexander Holevo publishes a paper showing that n qubits can carry more than n classical bits of information, but at most n classical...
six-photon entanglement, eight-photon entanglement, and five-photon ten-qubit cat state. This spin up/down formulation was proposed by David Bohm, who...
terms of ancilla qubits, that can be used for example in quantum error correction. One notable example for the use of ancilla qubits in quantum computing...
two qubits, the phase of the second (target) qubit is conditioned on the state of the first (control) qubit. Because the phase of the second qubit is being...
initializations of qubits to known values, and possibly other actions. The minimum set of actions that a circuit needs to be able to perform on the qubits to enable...
demonstrate a 48 logical qubit processor. To perform computation, the atoms are first trapped in a magneto-optical trap. Qubits are then encoded in the...
which are based on the quantum bit "qubit". Qubit is somewhat analogous to the bit in classical computation. Qubits can be in a 1 or 0 quantum state, or...