system
Given the following post, respond as if you're commenting on Reddit:
human
How are quantum computers actually implemented?

I have basic understanding of quantum information theory, however I have no idea how is actual quantum processor hardware made.

Tangential question - what is best place to start looking for such information? For theoretical physics I usually start with Wikipedia and then slowly go through references and related articles, but this approach totally fails me when I want learn something about experimental physics.
gpt
In superconducting quantum computing one typically uses Josephson junctions (superconducting tunnel junctions) to make anharmonic resonators that act as qubits. Junctions are made by litography like classical CPUs. Such qubits are prepared by microwave pulses that correspond to rotations on the Bloch sphere. Entanglement between qubits is generated by variable coupling (in the simplest case adjusting current through a Josephson junction changes its inductance and thus coupling). The Junctions are almost purely reactive so no loss is associated with them. Readout is usually done by reflecting a microwave pulse from a coupled microwave resonator and then determining the phase of the reflected pulse (which depends on the state of the qubit). Losses etc. limit the coherence time within which one has to do all the operations. The actual arrangements tend to be a bit more complicated, but that's the general idea. One gets pretty far with the experimental side of things by just doing classical circuit simulation. Understanding the many particle behavior between readouts maybe no so much.