Quantum computers require extremely low temperatures to operate effectively. Cooling is necessary to reduce thermal noise and maintain the delicate quantum states of the qubits, which are the building blocks of quantum computers. The specific cooling requirements vary depending on the type of qubit technology used in the quantum computer.
Superconducting qubits, one of the leading qubit technologies, typically require cooling to temperatures near absolute zero, which is approximately -273.15 degrees Celsius or -459.67 degrees Fahrenheit. Cooling to temperatures in the millikelvin range (thousandths of a Kelvin) or even microkelvin range (millionths of a Kelvin) is common for superconducting qubits. This level of cooling is achieved using sophisticated cryogenic systems, such as dilution refrigerators or adiabatic demagnetization refrigerators.
Other qubit technologies, such as trapped ions or topological qubits, may have different cooling requirements. Trapped ion qubits often operate at temperatures in the tens to hundreds of microkelvin range, achieved through laser cooling techniques and vacuum systems. Topological qubits, which are still in the early stages of development, may have different cooling requirements that are not yet fully determined.
In summary, cooling quantum computers to extremely low temperatures, close to absolute zero, is necessary to maintain the stability and coherence of the qubits. Cryogenic systems are used to achieve these low temperatures, but the specific cooling requirements can vary depending on the qubit technology being employed.