chaverondier
May26-04, 05:12 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>\n\nThe Quantum State Diffusion model of the individual evolution of open\nquantum systems introduced by Nicolas Gisin, Group of Applied Physics,\nUniversity of Geneva and Ian C Percival, Department of Physics, Queen\nMary and Westfield College, University of London (see for instance\nQuantum State Diffusion: from Foundations to Applications\nhttp://arxiv.org/abs/quant-ph/9701024 and Essay Review of Quantum\nState Diffusion by Ian Percival\nhttp://www.hpl.hp.com/techreports/2001/HPL-2001-7.pdf ) was motivated\nby a dynamical description of the measurement process. In this\napproach, the time evolution of the wavefunction |psi> of an\nindividual open quantum system is governed by the Ito stochastic\ndifferential equation\n\n|dpsi> = (-i/hbar) H |psi> dt\n+ sum_j [<L_j^ad> L_j – (1/2) L_j^ad L_j –(1/2) <L_j><L_j^ad>] |psi>\ndt ]\n+ sum_j [(L –<L_j>) |psi> dksi_j ]\n\n* where the L_j are the Lindblad operators modelling the\ninteractions of an individual quantum system in a shear state |psi>\nwith its environment\n* where L_j^ad denotes the adjoint Lindblad operator\n* where <L_j> = <psi |L_j| psi>\n* where H is the free Hamiltonian that would describe the evolution\nof this individual system if it were insulated\n* where the stochastic fluctuation or noise of the diffusion\nprocess is all contained in the standard normalized Wiener fluctuation\nterms dksi_j , which are of order (dt)^(1/2) and which satisfy the\nrelations\n<dksi_i dksi_j> = 0 <dksi_i dksi*_j> = delta_ij dt <dksi _j> =\n0\n* where dksi*_j denote the complex conjugate of dksi_j\n* where delta_ij denotes the delta Kronecker symbol\n\nMy question is that one.\n\nWhat are the quantum phenomena that give rise to the quantum noise\ndksi_j ?\n\nBernard Chaverondier\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>The Quantum State Diffusion model of the individual evolution of open
quantum systems introduced by Nicolas Gisin, Group of Applied Physics,
University of Geneva and Ian C Percival, Department of Physics, Queen
Mary and Westfield College, University of London (see for instance
Quantum State Diffusion: from Foundations to Applications
http://arxiv.org/abs/http://www.arxiv.org/abs/quant-ph/9701024 and Essay Review of Quantum
State Diffusion by Ian Percival
http://www.hpl.hp.com/techreports/2001/HPL-2001-7.pdf ) was motivated
by a dynamical description of the measurement process. In this
approach, the time evolution of the wavefunction |\psi> of an
individual open quantum system is governed by the Ito stochastic
differential equation
|dpsi> = (-i/\hbar) H |\psi> dt+ sum_j [<L_j^ad> L_j – (1/2) L_j^ad L_j –(1/2) <L_j><L_j^ad>] |\psi>dt ]+ sum_j [(L –<L_j>) |\psi> dksi_j ]
* where the L_j are the Lindblad operators modelling the
interactions of an individual quantum system in a shear state |\psi>
with its environment
* where L_j^ad denotes the adjoint Lindblad operator
* where <L_j> = <\psi |L_j| \psi>
* where H is the free Hamiltonian that would describe the evolution
of this individual system if it were insulated
* where the stochastic fluctuation or noise of the diffusion
process is all contained in the standard normalized Wiener fluctuation
terms dksi_j , which are of order (dt)^(1/2) and which satisfy the
relations
<dksi_i dksi_j> =<dksi_i dksi*_j> = \delta_ij dt <dksi _j> =
* where dksi*_j denote the complex conjugate of dksi_j
* where \delta_ij denotes the \delta Kronecker symbol
My question is that one.
What are the quantum phenomena that give rise to the quantum noise
dksi_j ?
Bernard Chaverondier
quantum systems introduced by Nicolas Gisin, Group of Applied Physics,
University of Geneva and Ian C Percival, Department of Physics, Queen
Mary and Westfield College, University of London (see for instance
Quantum State Diffusion: from Foundations to Applications
http://arxiv.org/abs/http://www.arxiv.org/abs/quant-ph/9701024 and Essay Review of Quantum
State Diffusion by Ian Percival
http://www.hpl.hp.com/techreports/2001/HPL-2001-7.pdf ) was motivated
by a dynamical description of the measurement process. In this
approach, the time evolution of the wavefunction |\psi> of an
individual open quantum system is governed by the Ito stochastic
differential equation
|dpsi> = (-i/\hbar) H |\psi> dt+ sum_j [<L_j^ad> L_j – (1/2) L_j^ad L_j –(1/2) <L_j><L_j^ad>] |\psi>dt ]+ sum_j [(L –<L_j>) |\psi> dksi_j ]
* where the L_j are the Lindblad operators modelling the
interactions of an individual quantum system in a shear state |\psi>
with its environment
* where L_j^ad denotes the adjoint Lindblad operator
* where <L_j> = <\psi |L_j| \psi>
* where H is the free Hamiltonian that would describe the evolution
of this individual system if it were insulated
* where the stochastic fluctuation or noise of the diffusion
process is all contained in the standard normalized Wiener fluctuation
terms dksi_j , which are of order (dt)^(1/2) and which satisfy the
relations
<dksi_i dksi_j> =<dksi_i dksi*_j> = \delta_ij dt <dksi _j> =
* where dksi*_j denote the complex conjugate of dksi_j
* where \delta_ij denotes the \delta Kronecker symbol
My question is that one.
What are the quantum phenomena that give rise to the quantum noise
dksi_j ?
Bernard Chaverondier