Kerr-free, 3-wave mixing Josephson dipole element*

A necessary requirement for any quantum computation architecture is the ability to perform efficient quantum operations. For superconducting qubits, quantum-limited amplification and conversion operations can be realized with a quadrupole Josephson junction element behaving as a loss-less three-wave mixer, the Josephson Ring Modulator (JRM). A recent approach for through-only amplification requires the application of multiple strong microwave pump tones to the JRM. In practice, unwanted fourth order Kerr nonlinearities jeopardize delicate frequency matching conditions. We present a novel dipole circuit element with third order nonlinearity, which implements three-wave mixing without the addition of harmful Kerr terms. In addition to reducing power dependent frequency shifts, such a pure three-wave mixer can be tessellated for increased dynamic range or bandwidth. Experimental results for a non-degenerate amplifier based on the proposed pure third order non-linearity will be reported.