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Deterministic Creation of Macroscopic Cat States.

Lombardo D, Twamley J - Sci Rep (2015)

Bottom Line: Despite current technological advances, observing quantum mechanical effects outside of the nanoscopic realm is extremely challenging.In this work we develop a completely deterministic method of macroscopic quantum state creation.It is found that by using a Bose-Einstein condensate as a membrane high fidelity cat states with spatial separations of up to ∼300 nm can be achieved.

View Article: PubMed Central - PubMed

Affiliation: Centre for Engineered Quantum Systems, Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia.

ABSTRACT
Despite current technological advances, observing quantum mechanical effects outside of the nanoscopic realm is extremely challenging. For this reason, the observation of such effects on larger scale systems is currently one of the most attractive goals in quantum science. Many experimental protocols have been proposed for both the creation and observation of quantum states on macroscopic scales, in particular, in the field of optomechanics. The majority of these proposals, however, rely on performing measurements, making them probabilistic. In this work we develop a completely deterministic method of macroscopic quantum state creation. We study the prototypical optomechanical Membrane In The Middle model and show that by controlling the membrane's opacity, and through careful choice of the optical cavity initial state, we can deterministically create and grow the spatial extent of the membrane's position into a large cat state. It is found that by using a Bose-Einstein condensate as a membrane high fidelity cat states with spatial separations of up to ∼300 nm can be achieved.

No MeSH data available.


Related in: MedlinePlus

A depiction of the Membrane in the Middle setup is shown in two separate cases.The top cavity contains a reflective membrane while the bottom contains a transmissive membrane. The switch represents the control over the membrane’s opacity, where ‘on’ corresponds to a reflective membrane and ‘off’ to a transmissive membrane.
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f1: A depiction of the Membrane in the Middle setup is shown in two separate cases.The top cavity contains a reflective membrane while the bottom contains a transmissive membrane. The switch represents the control over the membrane’s opacity, where ‘on’ corresponds to a reflective membrane and ‘off’ to a transmissive membrane.

Mentions: There is one, yet to be mentioned, limiting factor which hinders almost all of the current cat state creation schemes: they all involve measurement and thus are probabilistic. This is a severe drawback as the overall probability for success of the protocol exponentially decreases with the size of the cat state desired27. In this work a novel, completely deterministic method of creating cat states of the position of a macroscopic object will be proposed. These states will be created by exploiting properties in the optomechanical Membrane In The Middle (MITM) setup16. It will be shown that by controlling the membrane’s opacity its displacement can be driven at a rate proportional to the number of photons in the system. This will be achieved by effectively switching the membrane’s opacity between a reflective and a transparent state, as shown in Fig. 1. This technique will be used as a mechanism to create and deterministically grow the spatial extent of a quantum cat state. Before a cat state is produced, however, to ensure that the lifetime of the state is not limited by the finesse of the optical cavity the scheme requires disentanglement of the membrane’s final position from the two cavity modes. Disentangling such a state using the MITM model alone is extremely challenging experimentally, essentially requiring the membrane’s opacity to be also spatially dependent. Instead, an alternative deterministic disentanglement protocol will be proposed as the final step in creating the cat state. As a means of illustrating the cat state creation protocol a schematic experimental setup using optical light will be discussed . Finally, using a BEC type membrane, it will be shown that the proposed scheme is capable of creating high fidelity cat states with spatial displacements of up to ~300 nm using only a small photon occupation.


Deterministic Creation of Macroscopic Cat States.

Lombardo D, Twamley J - Sci Rep (2015)

A depiction of the Membrane in the Middle setup is shown in two separate cases.The top cavity contains a reflective membrane while the bottom contains a transmissive membrane. The switch represents the control over the membrane’s opacity, where ‘on’ corresponds to a reflective membrane and ‘off’ to a transmissive membrane.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4561959&req=5

f1: A depiction of the Membrane in the Middle setup is shown in two separate cases.The top cavity contains a reflective membrane while the bottom contains a transmissive membrane. The switch represents the control over the membrane’s opacity, where ‘on’ corresponds to a reflective membrane and ‘off’ to a transmissive membrane.
Mentions: There is one, yet to be mentioned, limiting factor which hinders almost all of the current cat state creation schemes: they all involve measurement and thus are probabilistic. This is a severe drawback as the overall probability for success of the protocol exponentially decreases with the size of the cat state desired27. In this work a novel, completely deterministic method of creating cat states of the position of a macroscopic object will be proposed. These states will be created by exploiting properties in the optomechanical Membrane In The Middle (MITM) setup16. It will be shown that by controlling the membrane’s opacity its displacement can be driven at a rate proportional to the number of photons in the system. This will be achieved by effectively switching the membrane’s opacity between a reflective and a transparent state, as shown in Fig. 1. This technique will be used as a mechanism to create and deterministically grow the spatial extent of a quantum cat state. Before a cat state is produced, however, to ensure that the lifetime of the state is not limited by the finesse of the optical cavity the scheme requires disentanglement of the membrane’s final position from the two cavity modes. Disentangling such a state using the MITM model alone is extremely challenging experimentally, essentially requiring the membrane’s opacity to be also spatially dependent. Instead, an alternative deterministic disentanglement protocol will be proposed as the final step in creating the cat state. As a means of illustrating the cat state creation protocol a schematic experimental setup using optical light will be discussed . Finally, using a BEC type membrane, it will be shown that the proposed scheme is capable of creating high fidelity cat states with spatial displacements of up to ~300 nm using only a small photon occupation.

Bottom Line: Despite current technological advances, observing quantum mechanical effects outside of the nanoscopic realm is extremely challenging.In this work we develop a completely deterministic method of macroscopic quantum state creation.It is found that by using a Bose-Einstein condensate as a membrane high fidelity cat states with spatial separations of up to ∼300 nm can be achieved.

View Article: PubMed Central - PubMed

Affiliation: Centre for Engineered Quantum Systems, Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia.

ABSTRACT
Despite current technological advances, observing quantum mechanical effects outside of the nanoscopic realm is extremely challenging. For this reason, the observation of such effects on larger scale systems is currently one of the most attractive goals in quantum science. Many experimental protocols have been proposed for both the creation and observation of quantum states on macroscopic scales, in particular, in the field of optomechanics. The majority of these proposals, however, rely on performing measurements, making them probabilistic. In this work we develop a completely deterministic method of macroscopic quantum state creation. We study the prototypical optomechanical Membrane In The Middle model and show that by controlling the membrane's opacity, and through careful choice of the optical cavity initial state, we can deterministically create and grow the spatial extent of the membrane's position into a large cat state. It is found that by using a Bose-Einstein condensate as a membrane high fidelity cat states with spatial separations of up to ∼300 nm can be achieved.

No MeSH data available.


Related in: MedlinePlus