Is CPT symmetry still valid for macroscopic physics?

[swansont]

44 minutes ago, Duda Jarek said:

From perspective after CPT symmetry the photons would travel toward CPT(target on the left)

That’s only time reversal symmetry. You haven’t applied the parity transformation.

 

 

[Duda Jarek]

By "CPT(target on the left)" I have meant with applied all 3 symmetries.

Or let us look from perspective of of radiation pressure : <E x H>/c, if ring laser creates positive radiation pressure, from perspective after CPT doesn't it mean negative?

[swansont]

1 hour ago, Duda Jarek said:

 

Or let us look from perspective of of radiation pressure : <E x H>/c, if ring laser creates positive radiation pressure, from perspective after CPT doesn't it mean negative?

No. With the t reversal, the excited atom in the target emits a photon.

[Duda Jarek]

6 minutes ago, swansont said:

No. With the t reversal, the excited atom in the target emits a photon.

Exactly, excited target usually deexcite in isotropic way, due to laser should additionally accordingly to the stimulated emission equation on the left - negative radiation pressure should increase probability of deexcitation in this direction, reducing monitored intensity seen by detectors around this target.

[swansont]

2 hours ago, Duda Jarek said:

Exactly, excited target usually deexcite in isotropic way, due to laser should additionally accordingly to the stimulated emission equation on the left - negative radiation pressure should increase probability of deexcitation in this direction, reducing monitored intensity seen by detectors around this target.

Why would there be stimulated emission under time reversal?

[Duda Jarek]

Looking at the diagram, absorption equation applies to the central and right targets (shifted behind right mirror), the emission equation to the central - the question is if also to the left (shifted behind left mirror).

From CPT perspective the equations would switch, the absorption equation would apply to CPT(central target) and to CPT(target on the left) - the latter means without CPT the emission equation would apply to the target on the left.

 

While <E x H>/c radiation pressure can be negative (e.g. https://scholar.google.pl/scholar?q=negative+radiation+pressure ), turns out there are lots of optical pulling experiments, beside optical tweezers awarded with 2018 Nobel Prize, here is good summary: https://opg.optica.org/oe/fulltext.cfm?uri=oe-31-2-2665&id=525052

Quote

About 10 years ago, optical pulling force (i.e. optical tractor beam) emerged [10–12] as an attractive and popular concept, not only because the counterintuitive feature but also the profound mechanism underneath and promising applications. In the recent several years, a variety of optical pulling schemes have been proposed mainly based on the physics of momentum transfer and energy transfer. On the one hand, as for the momentum transfer path, Bessel beams were proposed to pull elongated objects [13] and core–shell structures [14,15]. Fernandes et. al. reported an optical pulling using chiral light [16]. Enhancement of optical pulling force was reported using optically bound structures [17]. Optical pulling in a periodic photonic crystal background was reported, which was originated from the self-induced backaction of the object to the self-collimation mode [18]. Long-range optical pulling of nanoparticle based on Bessel beam was achieve by simultaneously using several novel and compatible mechanisms [19]. Optical pulling mechanism via engineering the topology of light momentum in the background was also reported [20]. Besides, optical pulling can be also realized using the fluidic drag force and metamaterials (the so called “meta-tweezers”) that have provided numerous opportunities in compact multifunctional optical manipulations, such as trapping, transporting, sorting and imaging [21,22]. On the other hand, optical pulling based on photon energy transfer also appear with the assistance of surrounding medium including gas and liquid, in which the photophoresis induced optical pulling is a significant scheme. Photophoretic force discovered by Ehrenhaft has been widely used in optical manipulation [4,23,24]. When an absorptive object is irradiated by inhomogeneous light, asymmetrical temperature distribution is created, and then hot side will give a larger recoiling force than the cold side originated from the thermal motion of medium molecules. In rough comparison, the Photophoretic force imparted by the gas molecules is c/3υ times greater than the radiation pressure originated from the photon momentum transfer, where c is the speed of light and υ is the gas molecular velocity [25]. Shvedov et. al. achieved long-range polarization-controlled laser pulling of gold-coated hollow glass spheres [26]. Zhang et. al. demonstrated a new principle of the laser-induced hammer-hit vibration of a micron-sized black sphere in liquid glycerol [27]. Lu et. al. reported light-induced pulling and pushing of micro gold plate by the synergic effect of optical force and photophoretic force [28]. Up to now, based on the physics of momentum transfer and energy transfer, various optical pulling of small objects at the micro-nano scale have been demonstrated. However, optical pulling of a macroscopic object is challenging and is rarely reported.

Seems all of them is pulling of objects with light, while ring laser should have related by different - pulling of photons, negative photon pressure, external stimulated emission.

[swansont]

6 hours ago, Duda Jarek said:

Looking at the diagram, absorption equation applies to the central and right targets (shifted behind right mirror), the emission equation to the central - the question is if also to the left (shifted behind left mirror).

The left target gets no light.

6 hours ago, Duda Jarek said:

From CPT perspective the equations would switch, the absorption equation would apply to CPT(central target) and to CPT(target on the left) - the latter means without CPT the emission equation would apply to the target on the left.

The target on left was the target on the right before you apply the P transformation. It was absorption. It become emission.

 

[Duda Jarek]

In CPT perspective the absorption equation would act on CPT(target on the left), what means emission equation acts on it in standard perspective (no CPT).

This equation work only if there are excited atoms: N_2 > 0, hence we can use e.g. a lamp here continuously excited in corresponding spectrum - usually deexciting in isotropic way, opening the shutter additionally with the emission equation - increased probability of deexciting toward the laser, what would be seen as reduced intensity by detectors around.

[Duda Jarek]

Optical pulling allows to pull in optical tweezers, negative radiation pressure to pull solitons - some hypothetical application: 2WQC (two-way quantum computers) maybe solving NP problems (standard 1WQC might be bounded with e.g. Shor, Grover).

I would gladly discuss and generally am searching for collaboration in these topics, especially access to ring laser to test if it allows for negative photon pressure, what is required e.g. by CPT symmetry.

[Duda Jarek]

Separate paper about such 2WQC: https://www.researchgate.net/publication/372677599_Two-way_quantum_computers_adding_CPT_analog_of_state_preparation

As stimulated emission-absorption are CPT analogs, creating negative-positive radiation pressure ( https://en.wikipedia.org/wiki/Radiation_pressure#Radiation_pressure_from_momentum_of_an_electromagnetic_wave ), we can imagine (unidirectional) ring laser as a pump.

Below is such hydrodynamical analog - in pump with fluid running in circles, flow to split down is reduced by negative radiation pressure.

The question to test is if it also true for ring laser: if intensity from beam splitter down is changed by opening/closing the shutter?

If so, a bit more complex setting would lead to two-way quantum computers.

[Duda Jarek]

Talk about such potential more symmetric enhancement of quantum computers allowing to attack NP problems ( https://arxiv.org/pdf/2308.13522 , slides ) :

 

Edited August 30, 2023 by Duda Jarek