The Quantum Cat

Derek Steinberg

Rashid Ahmad, Nawaz, Sumaira

Schrödinger's Cat was proposed by Erwin Schrödinger, the infamous thought experiment in which a cat in a box was both alive and dead simultaneously illustrating a quantum phenomenon known as superposition. In 2013, Yakir Aharonov and his co-authors conceived of an experiment suggesting that a particle can be separated from its property. They called the effect a "Quantum Cheshire Cat" that has been experimentally verified in the succeeding year. The name Quantum Cheshire Cat is inspired from a fanciful character of the Cheshire Cat in "\textit{Alice's Adventures in Wonderland"} a novel written by Lewis Carroll where the grin of cat is found without a cat. An important question arises here. Once the grin of the Cheshire Cat is separated, is there any correlation still left between the grin and the cat? To answer the question we propose a thought experiment in which Quantum Cheshire Cat is also a Schrödinger's Cat existing in superposition of happy(smiling) and sad(frowning) states. We name this cat as a "Quantum Mona Lisa Cat" for the reason that historically it is presumed that Mona Lisa's portrait contains both characteristics of happy(smiling) and sad(frowning) and either is observed depending upon the mood of the observer. We show that property separated from particle behave as "Quantum Mona Lisa Cat".

Miao Zhang, Haijun Kang, Meihong Wang +3 more

The optical cat state plays an essential role in quantum computation and quantum metrology. Here, we experimentally quantify quantum coherence of an optical cat state by means of relative entropy and the l 1 norm of coherence in a Fock basis based on the prepared optical cat state at the rubidium D1 line. By transmitting the optical cat state through a lossy channel, we also demonstrate the robustness of quantum coherence of the optical cat state in the presence of loss, which is different from the decoherence properties of fidelity and Wigner function negativity of the optical cat state. Our results confirm that quantum coherence of optical cat states is robust against loss and pave the way for the application of optical cat states.

John Whitworth

Sara Riccio, Rincy Kunjumon, Riccardo Falsini +2 more

We present experimental and theoretical representation of quantum-like Schrödinger's cat states, by exploiting orbital angular momentum of the light. We investigated complex superposition as 3-Cat, 6-Cat and Fock-Cat states.

Henry Pierce Stapp