(**QU**antum **BIT**) A unit of computation in a quantum computer. Pronounced "**q**-bit," the bit in qubit is somewhat misleading, although when a qubit is read, it does collapse ("decohere") into a 0 or 1. However, for computation and prior to being observed, the qubit can be in a superposition state, which means multiple states at the same time measured by electron motion and direction.

Unlike classical bits, qubits are not used for storage. Data are transferred to the qubits for computation and then read out for answers. Rather than a charge or pulse of electricity in a bit, it is the electrons in the qubit that are manipulated based on the laws of quantum mechanics.

In addition, while a classical bit is made of transistors, there are different qubit designs and constructions.

**Each Qubit Adds Exponentially More Power**

Qubits function like artificial atoms, and unlike classical bits, each additional qubit adds much greater computational power. For example, while five bits in a classical computer provides 32 values, five qubits in a quantum computer may generate a million values. See binary values.

**Coherence Is the Goal**

Qubits must vibrate in unison, which is known as "coherence." As of 2024, there is approximately one coherence error in 100 steps. Extending coherence is the major goal of quantum computer scientists. See quantum coherence.

**A Description from an Expert**

Interviewed on "60 Minutes" in December 2023, renouned quantum physicist Michio Kaku describes the qubit by saying "there is a fantastic amount of information stored when you can look at all possible angles, not just up or down." Kaku's example is navigating a maze. In classical computing, the pathway to exit is determined by moving through the maze one turn at a time. In quantum computing, all possible routes are computed simultaneously. See quantum computing.

**From 433 to 100 Thousand Qubits**

Qubits function like artificial atoms, and unlike classical bits, each additional qubit adds much greater computational power. For example, while five bits in a classical computer provides 32 values, five qubits in a quantum computer may generate a million values. See binary values.

Qubits must vibrate in unison, which is known as "coherence." As of 2024, there is approximately one coherence error in 100 steps. Extending coherence is the major goal of quantum computer scientists. See quantum coherence.

Interviewed on "60 Minutes" in December 2023, renouned quantum physicist Michio Kaku describes the qubit by saying "there is a fantastic amount of information stored when you can look at all possible angles, not just up or down." Kaku's example is navigating a maze. In classical computing, the pathway to exit is determined by moving through the maze one turn at a time. In quantum computing, all possible routes are computed simultaneously. See quantum computing.

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