Molecular assembler creates perfect Qubit

Molecular Assembler

Last month, a New Zealand team was able, for the first time, to put two individual atoms to interact "gently" without colliding and without forcing the bar so they could react.

Now a similar technique has been used to make the atoms react in a very special way, creating a molecule in a perfectly characterized quantum state.


The team used optic tweezers - precisely controlled laser beams to manipulate atoms - to entrap and cool a sodium (Na) atom and a cesium (Cs) atom by pooling and fusing them into a molecule of NaC in a quantum state specific - in this initial experiment, in the lowest energy ground state.

Molecular Qubit

A molecule whose quantum state can be precisely controlled is a promising building block for quantum computers and promises to help researchers study the quantum details of chemical reactions.

Although most of the current qubits are ions - electrically charged atoms -, it is widely recognized that molecules can be qubits better than atoms . In fact, it has recently been shown that a triangular copper molecule is a perfect qubit .

As the tool is generic, taking individual atoms as inputs and fusing into a molecule in a desired state, the team of Professor Kang-Kuen Ni of Harvard University in the USA states that, in addition to a qubit maker, its device is a quantum molecular assembler.

Practical applications

Molecules built into the molecular assembler can serve as qubits capable of storing information for a long time in their highly tuned internal states, which are insensitive to environmental disturbances. And, thanks to the ability of the NaC molecules to interact with each other, each molecular qubit could easily "talk" with other qubits to perform logical operations.


Another application is in the study of chemical reactions. The molecular assembler is used initially to prepare individual molecules in specific quantum states. Next, these molecules are pooled to verify, for example, how the rate of chemical reaction between them depends on these states.

Bibliography: Molecular Assembly of Ground-State Cooled Single Atoms L. R. Liu, JD Hood, Y. Yu, JT Zhang, K. Wang, Y.-W. Lin, T. Rosenband, Kang-Kuen Ni Physical Review X Vol .: 9, 021039 DOI: 10.1103 / PhysRevX.9.021039 Building one molecule from the reservoir of two atoms LR Liu, JD Hood, Y. Yu, JT Zhang, NR Hutzler , T. Rosenband, Kang-Kuen Ni Science Vol .: 360, Issue 6391, pp. 900-903 DOI: 10.1126 / science.aar7797