For first time, physicists 'trap’ individual molecules with astonishing precision : ScienceAlert

Bulky and difficult to wrestle with, molecules have long defied physicists’ attempts to coax them into a state of constrained quantum entanglement, whereby molecules are tightly bound even at a distance.

Now, for the first time, two separate groups have succeeded in trapping pairs of extremely cold molecules using the same method: microscopically precise optical 'tweezer traps’.

Quantum entanglement is a curious and fundamental phenomenon in the quantum realm that physicists are trying to build the first, commercial quantum computers.

All matter—from electrons to atoms, molecules, and entire galaxies—could theoretically be described as a spectrum of possibility before they were observed. Only by measuring an asset does the wheel of opportunity settle into a clear description.

When two objects become entangled, the property of one object — its spin, position, or momentum — immediately acts as a measure of the other, completely stopping both of their rotational possibilities.

So far, researchers have been able to trap entangled ions, photons, atoms and superconducting circuits in laboratory experiments. For example, three years ago, a team trapped trillions of atoms in a 'hot and chaotic’ gas. Impressive, but not very practical.

Physicists are also in a dilemma An atom and a molecule Before, and also Biological Complexes Found in plant cells. But controlling and manipulating pairs of individual molecules — with enough precision for quantum computing purposes — remains a daunting task.

It is difficult for molecules to cool down and interact readily with their surroundings, which means they easily break out of fragile quantum entangled states (called Disorder)

An example of those interactions Dipole-dipole interactions: The positive end of a polar molecule can be moved towards the negative end of another molecule.

But the same properties make molecules promising candidates for qubits in quantum computing because they offer new possibilities for computation.

„Their long-lived molecular spin states create strong qubits, while providing long-range dipole interactions between molecules Quantum entanglement,” Explains Harvard University physicist Yicheng Bao and colleagues, in their paper.

Qubits are a quantum version of classical computing bits that can take on the value 0 or 1. Qubits on the other hand can be mentioned Many possible combinations 1 and 0 at the same time.

By entangling qubits, their integrated quantum dimming 1s and 0s can act as fast calculators in specially designed algorithms.

Molecules, being more complex entities than atoms or particles, have more intrinsic properties or states that can be combined together to form a qubit.

„This means that, in practical terms, there are new ways to store and process quantum information.” He says Yucai Lu, a graduate student in electrical and computer engineering at Princeton University, co-authored the second study.

„For example, a molecule vibrates and rotates in several modes. So, you can use these two modes to encode a qubit. If the molecular species is polar, two molecules can interact even if they are separated by space.”

Both teams created ultra-cold calcium monofluoride (CaF) molecules and then trapped them one by one in optical tweezers.

Using these tightly focused beams of laser light, the molecules were positioned in pairs, with one CaF molecule close enough to sense its partner’s long-range electric dipole interactions. This led to each pair of molecules being entangled in a complex quantum state when they were strangers.

The method, along with the precise manipulation of individual molecules, „paves the way for new versatile platforms for quantum technologies,” writes Augusto Smerzi, a physicist at Italy’s National Research Council, from a related perspective.

Smerzi is not involved in the research, but sees its potential. By enhancing the dipole interactions of molecules, the system could one day be used to create super-sensitive quantum sensors capable of detecting ultraweak electric fields, he says.

„Applications range from electroencephalography to measuring the brain’s electrical activity to monitoring changes in electric fields in the Earth’s crust to earthquake forecasting,” he said. speculates.

Two studies have been published Science, Here And Here.