Researchers at Lawrence Berkeley National Laboratory have developed a method using a femtosecond laser and hydrogen doping to create and control qubits in silicon, potentially revolutionizing quantum computing by enabling precise qubit placement and connectivity for scalable quantum networks and the quantum internet. Credit: SciTechDaily.com
Berkeley Lab’s new technique uses femtosecond lasers and hydrogen to precisely create qubits in silicon, advancing prospects for scalable
Kaushalya Jhuria in the lab testing the electronics that are part of the experimental setup used for making qubits in silicon. Credit: Thor Swift/Berkeley Lab
Quantum Computing’s Potential and Challenges
Quantum computers have the potential to solve complex problems in human health, drug discovery, and
Connecting qubits, however, has been challenging for the research community. Some methods form qubits by placing an entire silicon wafer in a rapid annealing oven at very high temperatures. With these methods, qubits randomly form from defects (also known as color centers or quantum emitters) in silicon’s crystal lattice. And without knowing exactly where qubits are located in a material, a quantum computer of connected qubits will be difficult to realize.
Breakthroughs in Qubit Creation and Control
But now, getting qubits to connect may soon be possible. A research team led by Lawrence Berkeley National Laboratory (Berkeley Lab) says that they are the first to use a femtosecond laser to create and “annihilate” qubits on demand, and with precision, by doping silicon with hydrogen.
The advance could enable quantum computers that use programmable optical qubits or “spin-
An artistic depiction of a new method to create high-quality color-centers (qubits) in silicon at specific locations using ultrafast laser pulses (femtosecond, or one quadrillionth of a second). The inset at the top-right shows an experimentally observed optical signal (photoluminescence) from the qubits, with their structures displayed at the bottom. Credit: Kaushalya Jhuria/Berkeley Lab