/ News, Research

Nature Physics published: Anisotropic exchange interaction of two hole-spin qubits


First demonstration of a 2Q gate with holes in Silicon! In a fin field-effect transistor, the workhorse device of today’s semiconductor industry.

The exchange is anisotropic because of the spin–orbit interaction. Upon tunnelling from one quantum dot to the other, the spin is rotated by almost 180 degrees. The exchange Hamiltonian no longer has the Heisenberg form and can be engineered such that it enables two-qubit controlled rotation gates without a trade-off between speed and fidelity. This ideal behaviour applies over a wide range of magnetic field orientations, rendering the concept robust with respect to variations from qubit to qubit, indicating that it is a suitable approach for realizing a large-scale quantum computer.

Collaboration between IBM Zurich, Nanofabrication, and Uni Basel, Experiments and Theory. 

Publication: Geyer, Hetenyi, Bosco, Camenzind, Eggli, Fuhrer, Loss, Warburton, Zumbühl and Kuhlmann, Nature Physics, May 6, 2024.