QC Flashcards
What is a qubit and what can be used as qubits?
A qubit is the basic unit of quantum information. Any system that can enter a state of superposition and whose quantum-physical properties can be utilized can be used as qubits, such as particles or superconducting current loops. For example, the spin state of electrons, either up or down, can be used.
Why do qubits in superposition need to be well-isolated from the external world?
Qubits in superposition need to be well-isolated from the external world (e.g., light and heat) to prevent disturbance of their state (quantum coherence). Maintaining quantum coherence is crucial for enabling qubits to perform multiple calculations simultaneously.
What are logical qubits and why are they used?
Logical qubits are made up of several physical qubits and are used for error correction. If the state of one qubit in a logical qubit is disturbed, the entire logical qubit’s state does not get disturbed, thereby maintaining the integrity of the computation.
What are some current implementations of quantum computers?
Google Sycamore (2019) is a quantum computer based on superconductivity and electrons, with 53 qubits. The Zuchongzhi (2021) quantum computer from China is based on optical circuits and photons, with 66 qubits. In Finland, IQM aims to build a 50-qubit quantum computer by 2024 at the Micronova center, a joint venture between VTT Technical Research Centre of Finland and Aalto University.
