Events at Physics
Quantum computing architectures with ten or more quantum bits (qubits) have been implemented using trapped ions and superconducting devices. The next milestone in the quest for a quantum computer is the realization of quantum error correction codes. Such codes will require a very large number of qubits that must be controlled and measured by means of classical electronics. One architectural aspect requiring immediate attention is the realization of a suitable interconnect between the quantum and classical hardware. In this talk, I will introduce the quantum socket, a three-dimensional wiring method for qubits with superior performance as compared to two-dimensional methods based on wire bonding. The quantum socket is based on spring-mounted micro wires – the three-dimensional wires – that connect electrically to a micro-fabricated chip by pushing directly on it. The wires have a coaxial geometry and operate well over a frequency range from DC to 10 GHz. I will present a detailed characterization of the quantum socket, with emphasis on generalized time-domain reflectometry, a new signal integrity tool developed in my lab. As a proof of concept for quantum computing applications, I will show a series of experiments where a quantum socket was used to measure superconducting resonators at a temperature of ~10 mK. I will also show preliminary results where a socket was used to characterize resonators fabricated from molecular beam epitaxy aluminum films on gallium arsenide substrates. In conclusion, I will give an outlook demonstrating how the quantum socket can be used to wire a quantum processor with a 10 × 10 qubit lattice and I will outline our present work toward the implementation of such a lattice.