Promises// පොරොන්දු
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The day
She remembers well
he said
“Will love you forever
And a day”
But Some vows
Start fading
As soon as they are made
All that remains
Faint Twine ...
Spring Security Authentication
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Spring Security Authentication *Security is one of the most vital concerns
for any organization. In this article, you will learn about authentication
and ...
“Unassigning” meaning
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This is the current process that my mind is running. This task’s purpose is
very simple: “unassign” meaning from past events. In the life of a person,
the ...
In regular computers, the smallest unit of information is a bit, which can be either a 0 or a 1 — like a coin showing heads or tails.
In quantum computers, we use something called a qubit (quantum bit). A qubit is like a magical coin that can be in a state of 0, 1, or both at the same time. This special state is called superposition.
A 300-qubit error-free quantum computer would have a Hilbert space of size:
2300≈1090 quantum states
For reference, that’s more than the number of atoms in the observable universe (~1080).
We're still in the NISQ (Noisy Intermediate-Scale Quantum) era, but advancing toward error-corrected systems—possibly reaching 10–100 logical qubits by the late 2020s.
Company
Reported Qubits
Usable (Logical or High-Fidelity) Qubits
Technology
IBM
1,121 (Condor chip, 2024)
~20–30 physical usable with error mitigation; logical qubits still limited
Superconducting
Google
~72 (Sycamore)
~10–20 high-fidelity for short circuits, no fully logical qubits yet
Superconducting
IonQ
~35 physical
20–25 usable with high fidelity (~99.9%)
Trapped Ion
Quantinuum
56 (H2)
~32 high-fidelity usable qubits, very stable
Trapped Ion
Rigetti
84+
Fewer than 10 high-quality qubits
Superconducting
D-Wave
5,000+
Specialized for quantum annealing, not gate-based QC
Quantum computers also use another strange trick called entanglement. If you entangle two qubits, changing one will instantly affect the other — even if they're far apart. It's like two magic coins that always match up, no matter how far apart they are.