Researchers at the Center for Quantum Nanoscience in Korea have made a significant breakthrough in the field of quantum computing by utilizing the capabilities of an atomic microscope. This unconventional approach involves dragging the tip of a scanning tunneling microscope (STM) over titanium atoms on a surface to perform quantum calculations.
The team successfully demonstrated the construction, coherent operation, and readout of coupled electron-spin qubits using the STM. By complementing each electron spin with a local magnetic field gradient from a nearby single-atom magnet, they were able to achieve coherent control of “remote” qubits that are outside the tunnel junction.
One of the key highlights of this research is the fast and efficient manipulation of qubits in an all-electrical fashion. The implementation of pulsed double electron spin resonance allowed the researchers to demonstrate single-, two-, and three-qubit operations with remarkable speed.
The researchers began their experiment by scattering titanium atoms on a magnesium oxide surface and mapping their positions using the high-resolution STM. Using the tip of the microscope, they rearranged three atoms into a triangle. By emitting microwave signals from the STM tip, they could control the spin of a single electron in one of the titanium atoms and make its spin interact with the spins in the other two atoms.
This breakthrough in atomic-scale qubit manipulation opens up exciting possibilities for future developments in quantum computing. The researchers believe that their approach can be extended to incorporate even more qubits, potentially reaching a scale of around 100 qubits. This expansion could involve manipulating spins in a combination of individual atoms and molecules.
While this approach may not immediately join the existing range of techniques and qubit modalities in quantum computing, it offers a unique perspective on the field. By utilizing the capabilities of an atomic microscope, the researchers have unlocked new potentials for quantum computing that may pave the way for further advancements in the future.
1. What is a scanning tunneling microscope (STM)?
A scanning tunneling microscope (STM) is a scientific instrument that allows scientists to observe and manipulate materials at the atomic scale. It works by scanning a sharp metal tip over the surface of a sample and measuring the tunneling current, which provides information about the material’s topography and electronic properties.
2. What are qubits?
Qubits, short for quantum bits, are the fundamental units of information in quantum computing. Unlike classical bits, which can represent either a 0 or a 1, qubits can exist in a superposition of both states simultaneously. This property of superposition enables quantum computers to perform computations exponentially faster than classical computers for certain problems.
3. How does the team manipulate qubits using the scanning tunneling microscope?
The team at the Center for Quantum Nanoscience manipulates qubits by using the tip of the scanning tunneling microscope to control the spin of electrons in individual titanium atoms. By emitting microwave signals from the microscope’s tip, they can interact the spins of different atoms and perform quantum operations. This all-electrical approach allows for fast and efficient manipulation of qubits.