Building single-atom qubits under a microscope

IBM Research made a breakthrough in controlling the quantum behavior of individual atoms, demonstrating a versatile new building block for quantum computation.

This is the first time a single-atom qubit has been achieved using a Scanning Tunneling Microscope (STM) which allows atoms to be viewed and moved individually. This is an important breakthrough because the STM can image and position each atomic qubit to precisely control the arrangement of nearby qubit atoms. The microscope works by scanning the ultra-sharp needle tip near a surface to sense the arrangement of individual atoms, and the needle tip can pull or carry atoms into desired arrangements.

These single-atom qubits are extremely sensitive to magnetic fields so they can also be used as quantum sensors to measure the subtle magnetism of nearby atoms. The scientists used this sensitivity to make qubits interact – or entangle – with each other and make a two-qubit device. (IBM)

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