The pseudogap is mysterious metallic state of electrons which appears above the critical temperature of correlated electron superconductors, most prominently in the lightly-hole-doped cuprates. I argue that the pseudogap is best understood as the finite temperature realization of a metallic ground state with a spin liquid character, andpresent a theory using a bi-layer of ancilla qubits. This theory leads to a variational wavefunction for the pseudogap state, to gauge theories for transitions and crossovers out of the pseudogap, and to a unifying perspective on the cuprate phase diagram.
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