Speaker
Description
A practical quantum computer, capable of solving disruptive problems, may require thousands to millions of qubits in order to execute the required quantum error correction. Scaling ion trap quantum computers to larger numbers of qubits has become a prominent area of research [1,2]. However, the number of ions that can be hosted on a single quantum computing module is limited by the size of the chip or wafer being used. Therefore a modular approach is of critical importance and requires quantum connections between individual modules. One approach has been to use a photonic link to probabilistically generate entanglement between remote modules; 94 % is the highest fidelity achieved so far at a connection speed of 182 1/s for modules that are separated by 2 m [4]. We present an alternative approach by making use of a quantum matter link in which ions themselves are transferred between adjacent quantum computing modules. Demonstrating this method, we achieved a connection speed of 2400 1/s over a distance of 692 μm with a transfer fidelity between modules of 99.999995%. We have also verified the coherence of the quantum state of the transferred ion using a Ramsey experiment. The connection speed is limited by the update rate of the DC control system (100 kS/s) and the DC filters (70 kHz cut-off frequency).
References
[1] Lekitsch, B., et al., Science Advances, 3(2), 1–12 (2017).
[2] Monroe, C., et al., Science, 339(6124), 1164–1169 (2013).
[3] Brown, K., et. al., Npj Quantum Information, 2(1), 16034 (2016).
[4] Stephenson, L., et al., Physical Review Letters, 124(11), 110501 (2020).
