chaverondier
Apr24-04, 11:22 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>I would like to know about the compatibility of a positive result to a\nprinciple of test of a possible quantum measurement determinism and\nnowadays knowlegde of quantum mechanics (with an apparent\nindeterminism asumed to be of statistical origin stemming from our\nignorance of the environment interacting with the measurement\napparatus). More specifically, let us consider a given measurement\napparatus dedicated to measure some observable of a given quantum\nsystem.\n\nAs long as unitary and linear quantum evolutions are assumed, the\ninteraction of the measurement apparatus with its environment is\ndeterministic. Hence, the decoherence process (eg the decrease of the\noff-diagonal terms of the density operator of the measured physical\nquantity when this density operator is expressed in the preferred\nHilbert basis associated with the considered measurement apparatus) is\ndeterministic too ( cf Kastler Brossel studies on decoherence\nhttp://www.lkb.ens.fr/recherche/qedcav/college/college.html ).\n\nNow, the decoherence process doesn\'t explain the final irreversible\nand apparently indeterminist "quantum choice" (following decoherence\nstage and ending the quantum measurement process). However, the\nassumption according to which the quantum state of the environment\ninteracting with a quantum system and a measurement apparatus may be\nthe contextual hidden variables (that possibly may determine uniquely\nthe quantum measurement outcomes) proves to be compatible with Bells\ninequalities violation provided an explicitly non local interpretation\nof quantum physics processes be assumed ( cf Douglas L. Hemmick\ndissertation "Hidden Variables and Non Locality in Quantum Mechanics"\nfor instance http://www.intercom.net/~tarababe/index.html mastered by\nprofessor Sheldon Goldstein )\n\nNow\n\n* let us assume this presently unproven possibility (but\nnevertheless seemingly compatible with nowadays knowledge\nhttp://plato.stanford.edu/entries/qm-bohm/ ) according to which\nquantum measurement processes may be deterministic, provided any\nsystem interacting with the quantum system and its measurement\napparatus be accounted for (which perhaps needs to account for the\nwhole universe, but never mind) and let us consider an experimentalist\nphysicist (believing in this possible hidden determinism of quantum\nmeasurement) trying to bias the quantum statistics of spin\nmeasurements for instance.\n\nTo meet this objective\n\n* he sends a coherent monochromatic laser beam in a 45° state of\npolarisation\n\n* he splits this beam thanks to a calcite blade into a 0° and 90°\nsuperposition of spin state and puts a photon detector behind each\npolarised component.\n\n* thanks to drastic conditions applied to the environment of this\nexperiment (very low temperature, electromagnetic shield, laboratory\nvacuum, high mechanical insulation against vibrations...environment\nmedium set in a Bose Einstein Condensate quantum state ? other\nforgotten constraints ?) the observer tries to compel the environment\nto stay, as much as possible, in a coherent and stable quantum state.\n\nMy question is that one. In this context, from a principle point of\nview, is that possible (thanks to this environment quantum state\ndrastic control attempt and without conflicting at least one of the\nknown possible quantum measurement interpretations) that two\nsuccessive photon spin measurement outcomes may have a slightly\ngreater probability to be the same rather than being different ?\n\nBernard Chaverondier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>I would like to know about the compatibility of a positive result to a
principle of test of a possible quantum measurement determinism and
nowadays knowlegde of quantum mechanics (with an apparent
indeterminism asumed to be of statistical origin stemming from our
ignorance of the environment interacting with the measurement
apparatus). More specifically, let us consider a given measurement
apparatus dedicated to measure some observable of a given quantum
system.
As long as unitary and linear quantum evolutions are assumed, the
interaction of the measurement apparatus with its environment is
deterministic. Hence, the decoherence process (eg the decrease of the
off-diagonal terms of the density operator of the measured physical
quantity when this density operator is expressed in the preferred
Hilbert basis associated with the considered measurement apparatus) is
deterministic too ( cf Kastler Brossel studies on decoherence
http://www.lkb.ens.fr/recherche/qedcav/college/college.html ).
Now, the decoherence process doesn't explain the final irreversible
and apparently indeterminist "quantum choice" (following decoherence
stage and ending the quantum measurement process). However, the
assumption according to which the quantum state of the environment
interacting with a quantum system and a measurement apparatus may be
the contextual hidden variables (that possibly may determine uniquely
the quantum measurement outcomes) proves to be compatible with Bells
inequalities violation provided an explicitly non local interpretation
of quantum physics processes be assumed ( cf Douglas L. Hemmick
dissertation "Hidden Variables and Non Locality in Quantum Mechanics"
for instance http://www.intercom.net/~tarababe/index.html mastered by
professor Sheldon Goldstein )
Now
* let us assume this presently unproven possibility (but
nevertheless seemingly compatible with nowadays knowledge
http://plato.stanford.edu/entries/qm-bohm/ ) according to which
quantum measurement processes may be deterministic, provided any
system interacting with the quantum system and its measurement
apparatus be accounted for (which perhaps needs to account for the
whole universe, but never mind) and let us consider an experimentalist
physicist (believing in this possible hidden determinism of quantum
measurement) trying to bias the quantum statistics of spin
measurements for instance.
To meet this objective
* he sends a coherent monochromatic laser beam in a 45° state of
polarisation
* he splits this beam thanks to a calcite blade into a 0° and 90°
superposition of spin state and puts a photon detector behind each
polarised component.
* thanks to drastic conditions applied to the environment of this
experiment (very low temperature, electromagnetic shield, laboratory
vacuum, high mechanical insulation against vibrations...environment
medium set in a Bose Einstein Condensate quantum state ? other
forgotten constraints ?) the observer tries to compel the environment
to stay, as much as possible, in a coherent and stable quantum state.
My question is that one. In this context, from a principle point of
view, is that possible (thanks to this environment quantum state
drastic control attempt and without conflicting at least one of the
known possible quantum measurement interpretations) that two
successive photon spin measurement outcomes may have a slightly
greater probability to be the same rather than being different ?
Bernard Chaverondier
principle of test of a possible quantum measurement determinism and
nowadays knowlegde of quantum mechanics (with an apparent
indeterminism asumed to be of statistical origin stemming from our
ignorance of the environment interacting with the measurement
apparatus). More specifically, let us consider a given measurement
apparatus dedicated to measure some observable of a given quantum
system.
As long as unitary and linear quantum evolutions are assumed, the
interaction of the measurement apparatus with its environment is
deterministic. Hence, the decoherence process (eg the decrease of the
off-diagonal terms of the density operator of the measured physical
quantity when this density operator is expressed in the preferred
Hilbert basis associated with the considered measurement apparatus) is
deterministic too ( cf Kastler Brossel studies on decoherence
http://www.lkb.ens.fr/recherche/qedcav/college/college.html ).
Now, the decoherence process doesn't explain the final irreversible
and apparently indeterminist "quantum choice" (following decoherence
stage and ending the quantum measurement process). However, the
assumption according to which the quantum state of the environment
interacting with a quantum system and a measurement apparatus may be
the contextual hidden variables (that possibly may determine uniquely
the quantum measurement outcomes) proves to be compatible with Bells
inequalities violation provided an explicitly non local interpretation
of quantum physics processes be assumed ( cf Douglas L. Hemmick
dissertation "Hidden Variables and Non Locality in Quantum Mechanics"
for instance http://www.intercom.net/~tarababe/index.html mastered by
professor Sheldon Goldstein )
Now
* let us assume this presently unproven possibility (but
nevertheless seemingly compatible with nowadays knowledge
http://plato.stanford.edu/entries/qm-bohm/ ) according to which
quantum measurement processes may be deterministic, provided any
system interacting with the quantum system and its measurement
apparatus be accounted for (which perhaps needs to account for the
whole universe, but never mind) and let us consider an experimentalist
physicist (believing in this possible hidden determinism of quantum
measurement) trying to bias the quantum statistics of spin
measurements for instance.
To meet this objective
* he sends a coherent monochromatic laser beam in a 45° state of
polarisation
* he splits this beam thanks to a calcite blade into a 0° and 90°
superposition of spin state and puts a photon detector behind each
polarised component.
* thanks to drastic conditions applied to the environment of this
experiment (very low temperature, electromagnetic shield, laboratory
vacuum, high mechanical insulation against vibrations...environment
medium set in a Bose Einstein Condensate quantum state ? other
forgotten constraints ?) the observer tries to compel the environment
to stay, as much as possible, in a coherent and stable quantum state.
My question is that one. In this context, from a principle point of
view, is that possible (thanks to this environment quantum state
drastic control attempt and without conflicting at least one of the
known possible quantum measurement interpretations) that two
successive photon spin measurement outcomes may have a slightly
greater probability to be the same rather than being different ?
Bernard Chaverondier