Encoding quantum information in the degrees of freedom of molecules opens a new avenue for quantum technologies. Starting from the simpler diatomic molecules and advancing to the more complex polyatomic molecules, we are interested in studying the coherence properties of these MoleQubits (molecular qubits). We hope these studies will shed light on fundamental questions regarding the interface between quantum and classical descriptions of our world.
We will explore new types of quantum superpositions in molecules that are not possible with atoms or any other type of quantum hardware. One example is putting a single molecule in a quantum superposition of two distinct nuclear-spin-isomer states. In other words, we will bring a molecule to a quantum state where it both has and doesn't have hyperfine energy levels. See here our latest publication on this topic.
The homonuclear diatomic molecule, 14N2, has rich nuclear-spin-isomer (NSI) configurations. 14N nuclei have a nuclear spin of 1, thus molecular nitrogen has three configurations of the NSI quantum number, I=0,1,2. The two NSI configurations of orthonitrogen (I=0,2) have a remarkably different spectrum: the I=0 molecule has no hyperfine structure, while in contrast, the I=2 molecule has a rich hyperfine structure. These two NSIs of the same molecule are considered distinct molecules. In a theoretical paper, we suggested and analyzed a scheme to coherently interconvert molecular nitrogen from one NSI configuration to another and create a coherent superposition of both NSI configurations.
This project is funded by the Israel Science Foundation (ISF), grant No. 1010/22.
A molecule that has both hyperfine and no-hyperfine energy levels. Each of the nuclei of the nitrogen molecule has a spin of 1; thus, the molecule has three configurations of the total-nuclear-spin quantum numbers, I=0,1,2. The electric-quadrupole hyperfine interactions create an avoided crossing that mixes the two different nuclear-spin-isomer molecules at a magnetic field of ~31 Gauss. Coherent transitions from a well-defined nuclear-spin-isomer state through the avoided crossing can interconvert and create superpositions of nitrogen with different total nuclear spins.