量子计算QUBIT4MATLAB4.01

QUBIT4MATLAB : MATLAB PACKAGE FOR QUANTUM INFORMATION/ QUANTUM MECHANICS BY GEZA TOTH This program package helps modeling spin chains, qubit registers, etc. according to non-relativistic quantum mechanics and some novel ideas from quantum information theory. In particular, it contains MATLAB routines for reordering qubits, for computing the reduced density matrix after removing some of the qubits, for partial transposition, etc. Most of the routines work also for qudits. It also has routines for handling GHZ states, cluster states, graph states, Dicke states, etc. Usage: Create a directory with the name QUBIT4MATLAB. Copy the routines into it. Then, using the "Set Path" menu item of the "File" menu, setup MATLAB such that it looks for commands in this directory. If you use it for your research, please cite it as G. Toth, Comput. Phys. Comm. 179, 430 (2008). For the list of functions please write help qubit4matlab For examples please see example1 example2 example3 Guide book is available at http://dx.doi.org/10.1016/j.cpc.2008.03.007 (only with subscription to CPC) http://uk.arxiv.org/abs/0709.0948 http://arxiv.org/abs/0709.0948 Commands added after the version above: su2, BES_Breuer, maxppt, optwitness, example_maxppt, example_optwitness + changes in proj_sym, proj_asym, smolinstate, schmidt Licence: bsd.txt Please send bug reports to toth@alumni.nd.edu with the subject qubit4matlab ---------------------------------------------- History of versions: QM versions: V1.0 12 Apr 2005 V1.1 14 June 2005 keep/remove: bug corrected new functions for qudits new functions for spin chains Name changed to QUBIT4MATLAB: QUBIT4MATLAB V1.0 1 Sept 2005 nm: bug corrected QUBIT4MATLAB V1.1 23 Sept 2005 example1/2/3 added addnoise: added negativity: added ising_free: small bug corrected QUBIT4MATLAB V1.2 26 Jan 2006 mineig: added maxeig: added spmqubitop: name changed to mqubitopsp printv: bug corrected (did not work correctly for complex coefficients.) qrvec: added qrproduct added interact added interactsp added twirl,twirl2 small bug corrected (the description did not fit what the routine was doing) concurrence added realign added QUBIT4MATLAB V2.0 02 Oct 2006 qrvec name changed to rvec qrproduct name changed to rproduct runitary added rdmat added grstate added thstate added ising added isingp added spising added spisingp added heisenberg added heisenbergp added spnnchain added spnnchainp added coll added spcoll added spnnchain added spnnchainp added splattice added splatticep added spsising2Dp added spinteract added ising_classical_ground added xy_classical_ground added bra added braket added ex added swapquidts added shiftquditsleft added shiftquditsright added reordervec added reorder more efficient with large state vectors (>10 qubits); can use sparse matrices; does not use dec2base for counting but uses a faster method. spreordermat added keep Before keep(rho,[1 2]) and keep(rho,[2 1]) gave the same result. Now they give results which are permutations of each other. (qubit 1 and qubit 2 are exchanged) decompose faster since does not use dec2base for counting twirl works for qudits twirl2 works for qudits quditop added spquditop added twoquditop added sptwoquditop added printv treshold can be given as a second parameter mestate added mmstate added mqubitop removed: obsolete; use quditop and twoquditop U_CNOT added U_H added concurrence added QUBIT4MATLAB V3.0 06 October 2007 maxsymsep bug in second part of search repaired (it did not reach the maximum, just a value close to it) va added contents typos corrected smolinstate added swapqudits bug corrected; did not work correctly for qudits, only for qubits addnoise works also for qdits for d>2 trnorm added maxsep works now also for quidts with dimension larger than 2 maxsymsep works now also for quidts with dimension larger than 2 mrealign added ccnr added proj_asym added proj_sym added BES_Horodecki3x3 added BES_Horodecki2x4 added BES_UPB3x3 added orthogobs added keep works for qudits maxsep parameters of the numerical search can be set by an extra argument maxsymsep parameters of the numerical search can be set by an extra argument maxbisep parameters of the numerical search can be set by an extra argument maxb parameters of the numerical search can be set by an extra argument optspinsq added QUBIT4MATLAB V3.01 10 September 2007 Some typos in help text are corrected. QUBIT4MATLAB V3.02 12 October 2007 maxsymsep bug concerning parameter setting corrected (default parameter set was not possible to overwrite) maxsymsep Gives also back the state giving the maximum. example3 improved QUBIT4MATLAB v3.03 25 April 2008 decompose help text corrected keep_nonorm added QUBIT4MATLAB v4.00 25 May 2009 proj_sym works for the multi-qubit case proj_asym works for the multi-qubit case su2 added BES_Breuer added maxppt added optwitness added example_maxppt added example_optwitness added QUBIT4MATLAB v4.01 7 July 2009 smolinstate normalisation is corrected (state was not normalized to trace=1) optwitness modified to work for slightly larger systems schmidt slighly changed: before it gave back the _square_ of the schmidt coefficients, no it gives back the coefficients themselves changing from GPL to BSD license