Why does quantum computing need so much cooling if photonic doesn't?

[Falcon]

Someone told me superconducting quantum computers need to be cooled to crazy temperatures but photonic ones don't. Why is cooling such a huge deal? What happens if you don't cool it enough?

[Hollow Tiger]

Quantum states are fragile. The slightest vibration or heat interaction destroys them through decoherence. Superconducting qubits work by maintaining delicate quantum states in electrical circuits. Heat is the enemy because thermal energy causes the qubit to lose its quantum properties

[HiggsField41]

Temperature has a direct relationship to thermal noise. At room temperature atoms vibrate violently disrupting quantum information. Cooling to near absolute zero reduces vibrations exponentially. At millikelvin temperatures thermal noise becomes manageable

[Matticus]

Photonic qubits use light particles. Photons are packets of energy that don't get disrupted by thermal noise the same way. A photon at room temperature stays a photon. No cooling needed. That's the fundamental physics advantage

[Zach91]

It's like trying to balance a pencil on its point. At room temperature everything vibrates. Cooling reduces vibrations. Below certain temperature the quantum state becomes stable. For superconducting this is around 15 millikelvin. For photonic room temperature works

[Carol84]

The cooling infrastructure is brutal. You need dilution refrigerators that cost millions of dollars. They consume enormous amounts of liquid helium. The operational cost is massive. One of the biggest reasons photonic is attractive

[TaxSeason37]

Decoherence happens when quantum information leaks into the environment. Heat causes decoherence. So you either eliminate heat through cooling or engineer qubits that resist decoherence through physics. Photonic resists through light properties. Superconducting fights through temperature

[Lewis_43]

Technically superconducting qubits have coherence times of microseconds to milliseconds. Photonic can have longer coherence times even without cooling because photons decohere slower. That's a real advantage not marketing

[Aaron_67]

The business case for photonic becomes obvious when you scale. Imagine needing to cool a million qubits. You can't. The infrastructure doesn't exist. But you could build a room-temperature photonic system. Economics force the choice

[Jeffy]

Trapped ions trap individual atoms electromagnetically. Slight heating causes atoms to move disrupting quantum states. But not as sensitive as superconducting. Temperature requirements are less extreme than superconducting but more than photonic

[QuantumToken24]

The beginner takeaway: quantum information is fragile. Superconducting trades cooling cost for mature technology. Photonic trades mature technology for no cooling. Engineering tradeoffs not magic