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Quantum computer is useless
(Fig.1) Today's noisy (= error-prone ) quantum computers cannot outperform noiseless (= errorless ) quantum simulators (= classical computers ). But the media lied.
Despite the useless hopeless quantum computers, the mainstream media spread fake news saying HSBC-IBM ( error-prone ) quantum computer showed advantage in predicting bond trading.
↑ This fishy HSBC-IBM quantum computer's fishy advantage is just overhyped fake news ( this-3rd~4th-paragraphs ).
↑ This research paper ( this-last-link ) on fake quantum advantage ↓
↑ p.8-right-3.2-2nd-paragraph says -- error-prone quantum
"Since today's (quantum computer) devices are still inherently noisy (= error-prone ) and may alter the generated feature outputs, we
also use a noiseless (= errorless ) quantum simulator running on a classical
computer (= superior classical computers ) to compare with"
↑ p.9 says -- still Not a quantum computer
This quantum computer had only 109 qubits (= one qubit takes only 0 or 1 value ), which is useless, far from useful millions of qubits ( this-4th-paragraph ). ← They used deceptive "hybrid (= almost classical )" computer, the useless quantum computer alone cannot calculate anything.
↑ p.9-left-3.2.2. says -- classical computer needed
"Since the
quantum hardware is susceptible to noise (= errors ),.. In this study, we apply two error mitigation methods" ← Classical computers were used to empirically mitigate errors of their useless quantum computers ( this-4th-paragraph )" ← so No quantum computer's advantage.
↑ p.14-left-2nd~3rd-paragraphs say -- errors useful accidentally ?
"The model
performance results for respectively generated fill probability... show
significant uplifts of out-of-sample test scores for models with
noisy (= error-prone ) quantum hardware-generated inputs over those with noiseless (= error-less ) quantum simulation or classical input" ← false results
"the results are still subject to many open questions. For instance, it is Not understood how exactly quantum hardware noise affects our particular quantum circuit, and it is unclear how resulting noise-encoded feature vectors may benefit the analysis of noisy financial observables. This requires further investigation." ← doubtful results
↑ This research result is wrong, so this paper's author also doubts this result.
Because unlike this (doubtful) paper's result, it is impossible that the current noisy (= error-prone ) quantum computer hardware gave better results than the noiseless (= errorless ) quantum computer's simulator (= on classical computer ).
The noiseless (= errorless ) quantum simulators (= classical computers ) represent the best ideal errorless quantum computers that still do not exist, which can never be outperformed by today's useless noisy (= error-prone ) quantum computers theoretically.
This-4~5th-paragraphs say -- No quantum advantage
"Yet HSBC conceded in its paper that the observed effect was purely empirical, caused by 'inherent noise (= errors )' in the process with No theoretical foundation. That means the much-touted result is most likely a cherry-picked example of selection bias, according to Aaronson,"
This-p.9-right-conclusion-1st-paragraph (in 2025 ) says
"The slightly better performance of the classical
simulation is expected, as the Aer simulator assumes an ideal,
noiseless quantum system (= better errorless classical computer ), while real quantum hardware (= worse ) is
inherently affected by noise and gate errors."
This recent research paper using the same IBM quantum hardware (9/19/2025) showed inferior quantum computer's hardware ↓
↑ p.10-right-last-paragraph says -- Error-prone quantum
"When executing on real (quantum) hardware, in contrast to the noisefree Aer simulator (= classical computer ),.... Omitting this delay can result in timing
conflicts, backend execution errors, and incorrect state transitions, all of which do not occur in simulation"
↑ p.13-left-2nd-paragraph says -- Erroneous quantum computer
" the hardware (= quantum computer ) runs exhibit a noisier (= more erroneous ) distribution"
"On hardware, noise, gate errors, and qubit decoherence further reduced the likelihood of consistently sampling the optimal trajectories"
↑ IBM noisy quantum computer hardware is inferior to the noisefree classical computer's simulator.
So this HSBC research's noisy (= error-prone ) quantum computer hardware accidentally happened to make better prediction due to unpredictable errors (= No real quantum advantage ) or the artificial illegitimate error-mitigation trick conducted by a classical computer's post-processing ( this-p.1-right-2nd-paragraph ).
As a result, No quantum computer advantage in bond trading, contrary to overhyped fake news just trying to make today's error-prone hopeless quantum computers look "promising".
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