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Quantum crash test dummies

James Whitfield describes how quantum chemistry algorithms are like crash test dummies.

In this Video, Professor James Whitfield describes quantum chemistry as being similar to crash test dummies: rather than solving lots of equations, some important quantum chemistry algorithms model the behavior of molecules very directly. We assign qubits to behave like parts of a quantum mechanical system, then “crash” them (apply the conditions we want to learn about), then measure the results to see what happened, just like sensors attached to crash test dummies help us learn about the dynamics of an automobile crash.

Intuitively, it might seem that to model a molecule, we might assign a qubit to each electron, or to each point in space. However, the states in quantum chemistry algorithms are a little bit different. Instead, with only a few qubits, we can get a very low-precision answer to a question, whereas with more qubits, we can get a higher-precision answer.


この動画では、James Whitfield教授が量子化学を自動車の衝突実験に例えて解説していきます。 いくつかの量子化学アルゴリズムは、古典アルゴリズムのように複数の方程式を解いたりはせず、直接的に分子の動きをモデル化します。 つまり、量子コンピュータの量子ビットを量子系のように振舞わし、(目的に合わせて条件を設定し)「衝突」させ、その後量子ビットの測定を行う事で、車の衝突実験で使われる人形と同じような結果を分子モデルで観察することが出来ます。

直感的に、分子モデルでは各量子ビットに対し電子や格子点を一つずつ割り当てると想像したかもしれません。 しかし実際は少し違います。少ない量子ビットを使った計算では、低い精度の解しか得られませんが、量子ビットの数を増やせばより高精度な数値解を得ることが可能になります。

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Understanding Quantum Computers

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