QC - For real?

Photo: INRS University

Scientists have built a microchip that can generate two entangled qudits each with 10 states, for 100 dimensions total, more than what six entangled qubits could generate.

Quantum computing, the holy grail of true parallel processing of the highest order, may finally be at hand if this innovative approach of bypassing the inherent fragility of qubits rings true.

Instead of creating quantum computers based on qubits that can each adopt only two possible options, scientists have now developed a microchip that can generate “qudits” that can each assume 10 or more states, potentially opening up a new way to creating incredibly powerful quantum computers, a new study finds.

Classical computers switch transistors either on or off to symbolize data as ones and zeroes. In contrast, quantum computers use quantum bits, or qubits that, because of the bizarre nature of quantum physics, can be in a state of superposition where they simultaneously act as both 1 and 0.

The superpositions that qubits can adopt let them each help perform two calculations at once. If two qubits are quantum-mechanically linked, or entangled, they can help perform four calculations simultaneously; three qubits, eight calculations; and so on. As a result, a quantum computer with 300 qubits could perform more calculations in an instant than there are atoms in the known universe, solving certain problems much faster than classical computers. However, superpositions are extraordinarily fragile, making it difficult to work with multiple qubits.

2 vs 6 using existing tech to make it happen, awesome. BRT has talked copiously about the potential of QC. Maybe this approach will make it a reality. If so, the Matrix looms.

Image: Nature

Researchers used the setup pictured above to create, manipulate, and detect qudits. The experiment starts when a laser fires pulses of light into a micro-ring resonator, which in turn emits entangled pairs of photons. Because the ring has multiple resonances, the photons have optical spectrums with a set of evenly spaced frequencies (red and blue peaks), a process known as spontaneous four-wave mixing (SFWM). The researchers were able to use each of the frequencies to encode information, which means the photons act as qudits. Each qudit is in a superposition of 10 possible states, extending the usual binary alphabet (0 and 1) of quantum bits. The researchers also showed they could perform basic gate operations on the qudits using optical filters and modulators, and then detect the results using single-photon counters.