What would happen if we try to make a quantum computer for higher temperatures? And what is the difference between a logical qubit and a physical qubit?
Higher temperatures allow physical systems to have higher thermal energies. As we have seen in the case of Majoranas, this introduces errors in the system.
A physical qubit is a physical degree of freedom that can take two values or a superposition of these two (|0> and |1>). On the other hand, a logical qubit is more of a mathematical concept: we use physical qubits to encode logical qubits. This means we will use logical qubits to perform quantum computation, but these are represented by physical qubits in a physical system.