Final answer:
The fidelity of transmon qubit readout for quantum error correction is expected to decrease with temperature due to the increase in thermal energy and entropy, which can disrupt the quantum states and the superconducting properties essential for precise readout.c) Decreases with temperature is the correct answer.
Step-by-step explanation:
The question pertains to the readout fidelity of a transmon qubit in the context of quantum error correction. It references the importance of maintaining low entropy in quantum systems, as well as the interplay between temperature and superconductivity.
The readout fidelity of a transmon qubit for quantum error correction is generally expected to decrease with temperature.
This is due to the fact that an increase in temperature can lead to a rise in entropy within the system, disrupting the delicate quantum states necessary for error correction. Furthermore, as the critical temperature is reached—the temperature below which a material behaves as a superconductor—the noise levels increase, which can further degrade the fidelity of quantum state measurement. It is important to note that temperature is just one of the factors that can influence readout fidelity; other factors like magnetic field strength (tesla), qubit material, and external disturbances play significant roles as well.