Quantum effects do occur inside CPUs, but they are typically not directly harnessed for computation in conventional CPUs used in classical computers. In classical CPUs, information is processed using classical bits, which are represented by electrical voltages or currents that can be either high or low, corresponding to the binary states of 0 and 1.
However, the transistors and other components within CPUs are governed by the principles of quantum mechanics. These components, such as semiconductors, operate based on quantum phenomena such as electron tunneling, which allows electrons to pass through barriers that would be classically impossible to overcome.
Additionally, in very small transistors and nanoscale structures, quantum effects can become more prominent. For example, quantum confinement effects can impact the behavior of electrons in nanoscale regions, leading to changes in electrical conductivity and other properties. These effects are often accounted for and managed in the design and fabrication of modern CPUs.
That said, the power of quantum computing comes from harnessing quantum effects more directly through the use of quantum bits, or qubits, which can exist in superposition and entangled states. This allows for parallel computation and specialized algorithms that can outperform classical computers in certain domains. Quantum computers are specifically designed to leverage these quantum effects, whereas classical CPUs primarily rely on classical physics to perform computations.