Computer scientists prove that heat destroys quantum entanglement

Relation to Decoherence and Classical Limit

• Several commenters relate the result to known models of dissipation/decoherence (e.g., Caldeira–Leggett), debating whether the high‑temperature limit is just “the classical limit.”
• Others stress the paper is “fully quantum”: the infinite‑temperature Gibbs state is maximally mixed, not necessarily “classical,” though it behaves classically regarding entanglement.

What the Result Actually Covers

• The theorem is about Gibbs (thermal equilibrium) states of many‑body systems: above a system‑dependent finite temperature, these states lie inside the convex hull of product states and become separable (unentangled).
• It applies specifically to spin / lattice systems in thermal equilibrium, not to, for example, freely propagating entangled photons.
• One commenter notes this implies a hot bath will fully disentangle an initially entangled system in finite time once it thermalizes.

Superposition, Measurement, and Schrödinger’s Cat

• Long discussion about what counts as a “measurement” and “observer.”
• Some argue any interaction that causes decoherence is effectively a measurement; no special role for consciousness.
• Others emphasize that decoherence alone does not resolve the measurement problem or explain non‑unitary “collapse.”
• Schrödinger’s cat is used to probe macroscopic superposition, isolation of the box, and whether collapse is relative to each observer or global.

Entanglement, Bell Tests, and Hidden Variables

• Multiple explanations of why entanglement is not just pre‑set correlated states, referencing Bell tests and CHSH‑type games.
• Superdeterminism is discussed as a loophole (global hidden state fixed since the Big Bang); some find it appealing, others find it extremely contrived and non‑testable.

Interpretations of Quantum Mechanics

• Many‑worlds, decoherence, and the idea that “collapse” is appearance from within an entangled universe are debated.
• Competing views: a single universal wavefunction vs. wavefunction as knowledge; relative vs. objective collapse remain unresolved.

Heat, Interaction, and Entanglement

• Clarification that heat transfer (radiation, conduction, etc.) involves interactions that can spread entanglement; high temperature in this work specifically destroys certain long‑range entanglement structures.
• A hot object may lose special quantum correlations while still being heavily entangled with its environment.