Superconducting qubits and temperature

Superconducting qubits and temperature Ask Question Asked 2 years, 2 months ago Modified 4 days ago Viewed 257 times 3 I would like to ask about the need of a low temperature for the operation of superconducting qubits. I know a superconducting qubit is made from basically a LC circuit and Josephson junction. So obviously, since Josephson junctions are made from superconducting materials, it needs a low temperature to function. However, as stated in the link (Would an ambient-pressure, room-temperature superconductor eliminate the need for a dil-fridge in transmon processors?), a low temperature is required not only for it to be superconducting but for it to reduce noises and protect the qubits from collapsing. Does this mean that superconducting qubits have relatively shorter coherence time and susceptible to noises compared to other qubits like photon based ones, which can be used at RT? Also, relating to this, I am guessing that a low temperature is required to keep the system quantum like explained here (How do we know that a superconducting circuit is a quantum system?). Is this correct? The energy separation of superconducting qubits is relatively small corresponding to the microwave range, but can you engineer the energy separation? Why does the current qubit uses microwave not other optical region? superconducting-quantum-computing Share Improve this question Follow asked Jan 3, 2024 at 13:55 Yukina 311 1 bronze badge Add a comment 1 Answer Sorted by: Highest score (default) Date modified (newest first) Date created (oldest first) 0 Does this mean that superconducting qubits have relatively shorter coherence time and susceptible to noises compared to other qubits like photon based ones, which can be used at RT? Yes, superconducting qubits are one of the lowest coherence times (SpinQuanta article. Pennylane, part of Xanadu, a photonics-based QC company, also has this explained in more detail Pennylane. An interesting consideration is that while operations on sc qubits are faster than other modalities (like trapped-ion),coherence times are shorter, exhibiting the tradeoffs between different qubit modalities. Also, relating to this, I am guessing that a low temperature is required to keep the system quantum like explained here (How do we know that a superconducting circuit is a quantum system?). Is this correct? The energy separation of superconducting qubits is relatively small corresponding to the microwave range, but can you engineer the energy separation? Why does the current qubit uses microwave not other optical region? Short answer, yes. Superconductivity, as you stated, requires extremely low temperatures. Sure, numbers like 15 mK sound low, but when you realize that is colder than negative four hundred degrees farenheit, I think that adds more scale. The exact energy separation can be engineered, to some extent, by device design, including the geometry of the circuit, capacitance, or inductance, and since the inherent properties of these qubits are in the microwave range, this is the primary means through which sc qubits have been engineered. Share Improve this answer Follow answered Nov 12, 2025 at 21:23 user21057 Add a comment Your Answer Sign up or log in Sign up using Google Sign up using Email and Password Post as a guest Name Email Required, but never shown Post Your Answer By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy. Start asking to get answers Find the answer to your question by asking. Ask question Explore related questions superconducting-quantum-computing See similar questions with these tags. The Overflow Blog Open source for awkward robots Domain expertise still wanted: the latest trends in AI-assisted knowledge for... Featured on Meta Logo updates to Stack Overflow's visual identity Linked 6 Would an ambient-pressure, room-temperature superconductor eliminate the need for a dil-fridge in transmon processors? 6 How do we know that a superconducting circuit is a quantum system? Related 21 What cryogenic systems are suitable for superconducting qubits? 5 Conditional Phase Gate Superconducting Qubits 7 What are the pros/cons of Trapped Ion Qubits, Superconducting Qubits and Si Spin Qubits? 9 What limits scaling down the size of superconducting qubits? 2 Physical realization of qubits with superconducting Josephson junctions 0 what is the elementary Lab devices (and their specifications) for building superconducting qubits? 3 Why superconducting qubits need periodic calibration? Hot Network Questions Cockroach carrying a spy video camera in a movie? Is this spell balanced by the consequence? Hard position for Stockfish to analyze How to measure a year without relying on the Earth's tilted axis? 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