Clipped from: Technology Review: Blogs: arXiv blog: How to Create Quantum Superpositions of Living Things

How to Create Quantum Superpositions of Living Things

First photons, atoms and molecules. Now physicists want to create a quantum superposition of a virus, which will allow them to perform Schrodinger's Cat experiment for real.
[...]
But why bother? Performing a Schrodinger's cat experiment would be fun (although not for the virus). Romero-Isart and pals go further and say the work will "experimentally address fundamental questions, such as the role of life in quantum mechanics,and differences between many-world and Copenhagen interpretations". Perhaps.

Clipped from: Schrödinger's cat - Wikipedia, the free encyclopedia

Schrödinger's cat is a thought experiment, often described as a paradox, devised by Austrian physicist Erwin Schrödinger in 1935. It illustrates what he saw as the problem of the Copenhagen interpretation of quantum mechanics applied to everyday objects.

Schrödinger's Cat: A cat, along with a flask containing a poison, is placed in a sealed box shielded against environmentally induced quantum decoherence. If an internal Geiger counter detects radiation, the flask is shattered, releasing the poison that kills the cat. The Copenhagen interpretation of quantum mechanics implies that after a while, the cat is simultaneously alive and dead. Yet, when we look in the box, we see the cat either alive or dead, not a mixture of alive and dead.

Clipped from: YouTube - Schrodinger's Cat for real

Clipped from: Skeptic's Play: Intro to the Quantum Measurement Problem

Intro to the Quantum Measurement Problem

The Copenhagen Interpretation
[...] According to this interpretation, particles can be described by their wavefunctions. Wavefunctions behave like waves. They propagate around walls, and can go through multiple slits simultaneously. They can diffract and interfere with themselves.

Unlike normal waves, we cannot observe wavefunctions directly. If we try to observe a wavefunction, something called "wavefunction collapse" occurs. When a wavefunction collapses, it suddenly becomes like a particle.[...]

Clipped from: Skeptic's Play: Quantum superposition

Quantum superposition

Superposition may sound really weird, but mathematically, it's not weird at all. Schrodinger's equation, the equation that defines quantum mechanics, has the property that if you take any two wavefunctions and add them together, you'll get another wavefunction. So if you take one wavefunction with energy E₁ and another wavefunction with energy E₂, and add them together, you get a mixed state which has a superposition of energy levels E₁ and E₂ simultaneously!

[...]
If you actually try to measure the energy of a mixed state, you are guaranteed to observe one and only one energy. If you have a particle that is partly in the E₁ state and partly in the E₂ state, the way we interpret that is that there is a certain probability of measuring E₁ and a certain probability of measuring E₂. As soon as we measure it, the particle changes into a pure state again. This is called wavefunction collapse, which is the doorway to many of the philosophical questions that loom around quantum mechanics.

Clipped from: [0909.1469] Towards Quantum Superposition of Living Organisms

Title: Towards Quantum Superposition of Living Organisms

Authors: Oriol Romero-Isart, Mathieu L. Juan, Romain Quidant, J. Ignacio Cirac

The most striking feature of quantum mechanics is the existence of superposition states, where an object appears to be in different situations at the same time. Up to now, the existence of such states has been tested with small objects, like atoms, ions, electrons and photons, and even with molecules. Recently, it has been even possible to create superpositions of collections of photons, atoms, or Cooper pairs. Current progress in optomechanical systems may soon allow us to create superpositions of even larger objects, like micro-sized mirrors or cantilevers, and thus to test quantum mechanical phenomena at larger scales. Here we propose a method to cool down and create quantum superpositions of the motion of sub-wavelength, arbitrarily shaped dielectric objects trapped inside a high--finesse cavity at a very low pressure. Our method is ideally suited for the smallest living organisms, such as viruses, which survive under low vacuum pressures, and optically behave as dielectric objects. This opens up the possibility of testing the quantum nature of living organisms by creating quantum superposition states in very much the same spirit as the original Schr\"odinger's cat "gedanken" paradigm. We anticipate our essay to be a starting point to experimentally address fundamental questions, such as the role of life in quantum mechanics, and differences between many-world and Copenhagen interpretations.