Today's quantum computers are useless, too error-prone to simulate anything.

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Quantum computer is useless

(Fig.1)  Today's error-prone quantum computers with only small numbers of qubits are useless, unable to simulate anything, contrary to hypes.

Today's quantum computers are useless, too error-prone to simulate anything.

Today's quantum computers with small numbers of qubits (= still Not computers ) are useless, too error-prone to simulate anything such as drug, medicine, molecules, AI.. contrary to hypes ( this-p.3-left-2nd-paragraph ).

This-middle-The challenges of quantum computing (2024) says "quantum computing is still in its infancy, and there are significant challenges to overcome..., it is susceptible to noise (= errors )"

No quantum computer's advantage.

Quantum computer's supremacy or advantage is impossible (forever).

This-9~11th-paragraphs say
"Quantum computing is still very early, and quantum computers have yet to demonstrate a practical advantage over supercomputers"  ← No quantum advantage.

The alleged quantum computers' simulations are fake, which were conducted by practical classical computers as (misleading) hybrid or quantum simulators.

This-1st-paragraph (2024) says
"it (= quantum computing ) still lacks the speed and precision of classical computers, leading to the exploration of hybrid quantum-classical computation (= just classical computers )"

(Fig.2)  A noiseless (= errorless ) ideal quantum simulator is a classical computer.  Today's quantum computers are useless, too noisy (= error-prone ).

Today's quantum computers are useless, too error-prone (= too noisy ) to outperform classical computers.

When the overhyped media says "quantum computers outperformed classical computers", it means practical classical computers' simulation of some quantum methods outperforming some deliberately-chosen slow classical method.

Today's quantum computers are useless, too error-prone (= noisy ) to simulate anything ( this-2nd-paragraph,  this-p.2-2nd-paragraph ).

This-p.2-left-1~2nd-paragraphs (2025) say
" In the current NISQ (Noisy Intermediate-Scale Quantum) era, real-world quantum circuits are notably affected by various noises analogous to faults (= errors ) in classical circuits"

Quantum advantage is impossible forever.

Noiseless (= errorless ) quantum simulators are classical computers.

The practical errorless classical computers are often used as noiseless quantum simulators ( this-p.9-upper ) that always outperformed today's noisy quantum computers.
↑ So the noiseless quantum simulators are just classical computers, Not quantum computers.

This-p.6-right-IV saying "Qiskit noiseless classical simulator"
p.9-right-V saying "exact (state vector) classical simulator (= errorless noiseless classical computers called simulators )"

This-p.1-left-1st-paragraph says
"noiseless qubits can be routinely simulated on a laptop"

This-2nd-last-paragraph says
"noiseless weak.. is a classical simulation that allows sampling bitstrings computed by a given quantum circuit... Since No current prototype quantum computer is noiseless"

This-p.9-right-IV.1.1 says
"An ideal simulator (or ideal device) is an idealized quantum computer that is not affected by any noise channel such as decoherence, gate errors, or readout errors and which is numerically simulated on a classical machine"

Classical computers are also used as noisy quantum simulators of today's error-prone quantum computers.

Classical computers are often used as noisy quantum simulators mimicking today's error-prone useless quantum computers ( this-p.1-left-1st-paragraph,  this-2~4th-paragraphs ).

This-p.4-right-A. says
"using a quantum simulator (= classical computer ) in the idealized noiseless case ..,
We utilize a noisy simulator to understand how our approach would behave in a realistic noisy intermediate scale (NISQ) quantum computer, which is affected by multiple sources of noise from the environment and is prone to errors during computations"

This-p.11-left-2nd-paragraph says
"the noiseless (= classical ) simulator's VQE run converges to the correct result... Conversely, the noisy simulator, incorporating the full spectrum of hardware noise (= quantum computers' errors ) reproduced for the same hardware (= today's error-prone quantum computers ), struggled to maintain a consistent energy minimization pattern"

↑ The noiseless (= errorless ) classical computer's simulators always outperform today's noisy (= error-prone ) quantum computers.

(Fig.3)  Quantum computers simulating medicine, drugs mean classical computers used as (misleading) quantum simulators or hybrid quantum computers.

Quantum computer with only 2 useless qubits (= still Not a quantum computer ) cannot discover drugs, contrary to hypes.

They falsely treat a practical classical computer's simulation (+ using only 2 useless qubits ) as a (deceptive) hybrid quantum computer.

This news-lower-Not ready quite yet (7/29/2024) says
"using quantum computers for current drug discovery faces significant limitations. For example, quantum computing is still plagued by longer computational times and errors, which impede its accuracy and efficiency in drug discovery"  ← Quantum computers are useless.

↑ This research paper ↓

p.2-Fig.1 shows this research used also a classical computer (= today's useless quantum computer alone can do nothing ) as "hybrid computer".

p.4-Fig.3 shows this research used only 2 qubits (= just 2 bitstring,  ← still Not a quantum computer.  2 qubits alone cannot simulate anything ).

p.7-last-paragraph says "the time cost for quantum computers is larger than that for classical (= noiseless ) computers"  ← Classical computers were far faster than quantum computers, so No quantum speed-up.

Quantum computers are useless for breast cancer diagnosis, contrary to the misleading headline.

Hybrid quantum-classical algorithm was performed only by a classical computer.  Useless quantum computers were Not used in medicine after all.

This-lower-The need for real opus says
"First, the experiments were conducted on classical hardware using simulated quantum computing environments"  ← Useless quantum computers were Not used after all.

↑ This misleading "hybrid quantum-classical computer" was just a classical (= conventional ) computer ( this-p.11-last-paragraph ).

Today's quantum computers are completely useless for medicine or simulating something.

Just 5 qubits (= still Not a quantum computer ) cannot identify livers for transplant.

A practical classical computer's simulation of 5 qubits is misleadingly called "quantum computing".

The 1st paragraph of this hyped news (8/13/2024) says
"build a diagnostic system that combines quantum computing techniques with classical machine learning systems."  ← A practical classical computer is always necessary. Today's useless quantum computers alone can do nothing.

↑ This research paper ↓

p.4-Fig.1-(c) says 5 qubits  ← Just 5 qubits (= just 5 bitstring ) is still Not a quantum computer nor able to calculate anything.

p.6-right-3rd-paragraph says this research used Pennylane simulator, which is just a classical computer.

↑ So this research just used a classical computer for simulating some quantum algorithm, instead of using today's impractical quantum computers.

(Fig.4)  The overhyped media often treats the classical computer's simulation of some quantum methods as (fake) quantum computer's advantage.

Overhyped quantum computer advantage is fake, which is just a classical computer simulating some quantum method.  - IonQ

Insider brief of this hyped news (3/20/2025) says

"IonQ and Ansys demonstrated that a hybrid quantum-classical algorithm (= just a classical computer ), when simulated, can outperform classical methods (= Not outperform a classical computer ) in engineering simulations, achieving up to 12% faster processing in blood pump design tests."

Classical > Quantum

↑ This research paper ↓

p.1-abstract-2nd-paragraph says
"We also execute the VarQITE algorithm (= quantum algorithm ) on quantum hardware (IonQ Aria and IonQ Forte) and find that the results are comparable to (= did Not outperform, classical computer's ) noiseless and noisy simulations"

p.11-right-last-paragraph says
"Since QPU (= useless quantum computers ) executions can often take much longer than classical CPUs/GPUs"  ← Classical computers were much faster than today's quantum computers.

↑ So this research just showed a (noiseless) classical computer's simulation of some quantum method outperformed some deliberately-chosen slow classical method, Not that quantum computers outperformed classical computers.

This-updated version's p.12-left-last-paragraph and p.13-Fig.9 shows the noiseless classical computer gave more optimal solutions (= 0.0, = the first bar from the left, Fig.9-(A) ) than the error-prone IonQ-Forte quantum computer (= Fig.9-(B) ).  ← A classical computer outperformed the quantum computer (= still Not a computre ).

Just 6 error-prone qubits were easily outperformed by a classical computer's simulator.

6 error-prone qubits made a hybrid computer give inaccurate molecular energy values, which was easily outperformed by a errorless classical computer's simulator.

The 4~5th paragraphs of this news (10/17/2024) say

"VQE is a hybrid quantum-classical algorithm (= just classical computer ) that uses both quantum and classical computers to estimate the ground state energy of a molecular system. "

"researchers were able to simulate the magnetic structure of the molecule more effectively than classical simulations."  ← untrue, fake news.

↑ This research paper ↓

p.5-Fig.5 says just 6 qubits (= still Not a quantum computer nor able to calculate molecular energy ).

p.6-Fig.6 showed only a noiseless classical simulator (= QASM ) reached the exact energy value, while a IBM quantum computer hardware or a noisy simulator failed to give exact energy value.

↑ No quantum computer advantage.  Even the 6 error-prone qubits were enough to prevent the hybrid computer from giving accurate values, while a classical computer's simulator always gave exact values..

(Fig.5)  Instead of today's useless error-prone quantum computers, the practical classical computers are used as (misleading) hybrid quantum computers.

Just 5 error-prone qubits are useless, still Not a quantum computer.

5 error-prone qubits (= still Not a quantum computer ) prevented hybrid computer from giving right energy values predicted by a errorless classical computer.

This-Anderson model and why.. (10/2/2024) says
"they used a five-qubit nuclear magnetic resonance (NMR) quantum processor"  ← Just 5 qubits (= 5 bitstring ) is still Not a quantum computer.

This-middle-Prospects and challenges says
"Although quantum computers are still in the noisy intermediate-scale quantum era—prone to errors and limited by the number of qubits"  ← Today's error-prone quantum computers are noisy, useless.

↑ This research paper ↓

p.1-right-2nd-paragraph says " through a feedback loop that combines quantum and classical computations (for estimating some abstract quantum model )."  ← Hybrid classical computer.  Today's quantum computers alone can calculate nothing.

p.3-Fig.2 shows only 5 qubits (= still Not a quantum computer nor able to calculate anything ).

p.4-Fig.3-(a)(b)(c) showed these error-prone 5 qubits' results deviated from the exact theoretical values calculated by a classical computer's simulation..

↑ No quantum computer's advantage nor utility.  Even 5 qubits were too error-prone to give right answers.

Instead of useless 20 qubits (= still Not a quantum computer ), a classical computer's emulator was used for simulating a molecule.

The insider brief, 3rd, 7th paragraphs of this news (7/10/2024) say

"Hyperion-1 emulator.. 20 qubits (= still Not a quantum computer )"

" The Hyperion-1 emulator uses Genci supercomputers (= just a classical computer )"

"Next steps include deploying these algorithms on existing noisy (= quantum ) machines.."  ← Today's error-prone (= noisy ) quantum computers were useless (= so Not used ) for computing a molecule in this research after all.

See also IBM-Cleveland's fake quantum computer.

(Fig.6)  Today's quantum computers are useless, too error-prone to use for (hyped) AI, neural network, machine learning.

Quantum computing AI is overhyped, useless, unable to find molecules targeting cancer proteins.

A quantum computer with only 16 qubits is useless, easily outperformed by the precise classical computer's simulator.

The 6th paragraphs of this hyped news (1/27/2025) says
"To discover potential new drugs against KRAS (= cancer protein ), the researchers paired a quantum computer alongside classical computing methods to design new molecules."  ← Hybrid classical computer.  Quantum computers alone are useless.

↑ This research paper ↓

p.2-Fig.1d says
"A total of 1 million compounds (classical samples from the LSTM, quantum samples from QCBM on quantum hardware and simulated quantum samples on classical hardware) were evaluated"  ← classical computer was used as a simulator of quantum method called QCBM

p.5-left-the 5th-last-sentence says "they stop short of definitively proving a quantum advantage"  ← No quantum computer advantage.

p.14-Extended-Fig.1-(C) shows only 16 qubits (= still Not a quantum computer ) were used.

p.14-Extended-Fig.1-(A)(B) shows quantum simulator (= classical computer, QCBM-SIM ) outperformed quantum computer hardware (= HW ) in some success rates of predicting molecules (= SR, this-p.41-S3.2-Table 2 )

↑ A classical computer's simulator of the 16-qubit in quantum method outperformed the error-prone quantum computer hardware, so No quantum advantage.

Fake quantum advantage in AI finding breast cancers.

Just 9 qubits were easily outperformed by a noiseless classical computer's simulator.  No quantum computer's advantage.

This-7th-paragraph says
"The first area where quantum advantage (= wrong ) has been reached for AI tools is image classification. We recently published a peer-reviewed paper that a quantum algorithm (= Not conducted by quantum computers ) can better predict breast cancer than traditional AI."

↑ This research paper ↓

p.4-left-III says
"with kernel sizes of 2 × 2 (four qubits) and 3 × 3 (nine qubits)"  → Just 9 qubits can take only 2⁹ = 512 numbers (= one qubit can take only 0 and 1 bit value ), which can be easily simulated by today's classical computer, so No quantum advantage.

p.4-Fig.3(a) and p.6-Fig.4 show the noiseless classical computer's simulator of quantum method called DAOCNN gave the best accurate results (= AUC is a measure of accuracy = p.5-left-2nd-paragraph ).

↑ No advantage of the quantum computer with only 9 qubits that can be easily outperformed by a noiseless (= errorless ) classical computer's simulator.

Just 4 qubits (= still Not a quantum computer ) cannot outperform classical computers in neural network, contrary to hypes.

The 2nd paragraph of this hyped news (12/22/2024) says
"This hybrid quantum-classical model (= just classical computer )... in tasks involving pattern recognition and classification. The implications are significant, with potential (= still useless ) applications"

↑ This research paper ↓

p.1-abstract says 4-qubit quantum circuit (= just 4 qubits can take 2⁴ = 16 values, that can be easily simulated or outperformed by a classical computer ).

p.3-2nd-last-paragraph says
"While our work does Not aim to achieve computational supremacy,"  ← No quantum computer supremacy

(Fig.7)  Today's error-prone quantum computers cannot give right answers unless they illegitimately rely on classical computers as error mitigation (= Not error correction )

An errorless classical computer could easily outperform the quantum computer with 100 error-prone qubits in simulating particle collision.

The 3rd paragraph of this hyped news (3/17/2025) says
"They successfully used the technology to mimic basic parts of nuclear physics using IBM quantum computers with over 100 qubits (= still Not a quantum computer )."

↑ This research paper ↓

p.1-abstract-lower says "After introduction of an improved error-mitigation technique (= just classical computer's post-processing by guessing errors, Not legitimate quantum error correction, this-p.1-right-1st-paragraph  = scaling up is impossible ),.. charge-charge correlators obtained from the quantum computers are found to be in good agreement with (= did Not outperform ) classical matrix product state (= MPS ) simulations."

p.26-Fig.17 showed the error-prone quantum computer (= ibm_cusco ) could Not give the same exact values as the noiseless (= errorless ) MPS classical simulator.

↑ Today's error-prone quantum computers cannot outperform classical computers, even when classical computers are unfairly forced to imitate the illusory quantum computer's parallel universe calculations (= 100 qubits are said to use 2¹⁰⁰ illusory parallel universes for parallel calculations ).

Today's useless quantum computers cannot calculate particle physics. contrary to hypes.

Just 6 qubits is Not a quantum computer.  Only a classical computer's simulator was used in this research.

This hyped news-Limitations and future directions (3/8/2025) say
"The current generation of quantum hardware—.. does Not yet have the capacity to run these algorithms... indicate that even for relatively simple calculations, a quantum circuit may require millions of quantum gate operations and qubits that are currently beyond the reach of commercial devices"  ← Today's quantum computers are impractical.

↑ This-research paper ↓

p.20(or p.19) says 6-qubit.  ← still Not a quantum computer.

p.23-2nd-paragraph says "we ran noiseless simulations (= which is just a classical computer, so a quantum computer was Not used, after all )"

p.28-5th-paragraph says
"Our findings suggest that such applications are unlikely to be practical during the noisy intermediate-scale quantum (NISQ) era"  ← Today's error-prone quantum computers were too impractical to use for ( particle physics ) calculations.

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