Scientists at MIT, the University of Chicago and Columbia University, have taken a major step in the development of tailored qubits. They have demonstrated how a particular molecular family of qubits can be finely tuned over a broad spectrum, like turning a sensitive dial on a wide-band radio.
The team also outlines the underlying design features that enable exquisite control over these quantum bits.
The researchers’ work focuses on a specific group of molecules: those with a central chromium atom surrounded by four hydrocarbon molecules to form a pyramidlike structure. One advantage of a molecular qubit is that, like a tiny 3D-printed gadget, it can be engineered from the bottom up, giving the scientist freedom to tune the qubit for different functions.
A molecular qubit’s information is stored in its spin, a property of atomic-level materials. Scientists engineer the spin by adjusting—tuning—the arrangement of the molecule’s electrons, its electronic structure. The information enters the qubit as particles of light, or photons, and is encoded in the qubit’s spin. The spin-encoded information is then translated again into photons, to be read out.
Different photon wavelengths are more suitable for different applications. One wavelength may work better for biosensing applications, another for quantum communication. One of the molecular qubit’s key tuning dials is the ligand field strength, the strength of the bonds connecting the central metal atom to the surrounding hydrocarbons. (Phys.org)
The paper has been published in the Journal of the American Chemical Society.
