physics

Quantum tunneling of water

Quantum tunneling of water is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Quantum tunneling of water rather than just read about it. In short: The quantum tunneling of water occurs when water molecules in nanochannels exhibit quantum tunneling behavior that smears out the positions of the hydrogen atoms into a pair of correlated rings. In that state, the water molecules become delocalized around a ring and assume an unusual double top-like shape.

Key takeaways

Quantum tunneling of water belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Quantum tunneling of water to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Quantum tunneling of water from memory before moving on to harder problems.

Reference excerpt

The quantum tunneling of water occurs when water molecules in nanochannels exhibit quantum tunneling behavior that smears out the positions of the hydrogen atoms into a pair of correlated rings. In that state, the water molecules become delocalized around a ring and assume an unusual double top-like shape. At low temperatures, the phenomenon showcases the quantum motion of water through the separating potential walls, which is forbidden in classical mechanics, but allowed in quantum mechanics. The quantum tunneling of water occurs under ultraconfinement in rocks, soil and cell walls. The phenomenon is predicted to help scientists better understand the thermodynamic properties and behavior of water in confined environments such as water diffusion, transport in the channels of cell membranes and in carbon nanotubes.

History Quantum tunneling in water was reported as early as 1992. At that time it was known that motions can destroy and regenerate the weak hydrogen bond by internal rotations of the substituent water monomers. On 18 March 2016, it was reported that the hydrogen bond can be broken by quantum tunneling in the water hexamer. Unlike previously reported tunneling motions in water, this involved the concerted breaking of two hydrogen bonds. On 22 April 2016, the journal Physical Review Letters reported the quantum tunneling of water molecules as demonstrated at the Spallation Neutron Source and Rutherford Appleton Laboratory. First indications of this phenomenon were seen by scientists from Russia and Germany in 2013 based on the splitting of terahertz absorption lines of a water molecule captured in five-ångström channels in beryl. Subsequently, it was directly observed using neutron scattering and analyzed by ab initio simulations. In a beryl channel, the water molecule can occupy six symmetrical orientations, in agreement with the known crystal structure. A single orientation has the oxygen atom approximately in the center of the channel, with the two hydrogens pointing to the same side toward one of the channel's six hexagonal faces. Other orientations point to other faces, but are separated from each other by energy barriers of around 50 meV. These barriers, however, do not stop the hydrogens from tunneling among the six orientations and thus split the ground state energy into multiple levels.

References

Worked examples

Example 1 — a first encounter with Quantum tunneling of water

Start with the simplest possible case. Write down what Quantum tunneling of water claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Quantum tunneling of water before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Quantum tunneling of water ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Quantum tunneling of water

In research: Quantum tunneling of water appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Quantum tunneling of water in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Quantum tunneling of water is common in secondary-school and first-year university syllabi. It links to neighbouring topics Quantum chemistry, Water physics, so understanding it makes those chapters shorter.
In everyday life: Look for Quantum tunneling of water outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Quantum tunneling of water” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Quantum tunneling of water in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Quantum tunneling of water means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Quantum tunneling of water out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Quantum tunneling of water in simple terms?

Why does Quantum tunneling of water matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Quantum tunneling of water?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Quantum tunneling of water.