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Schrodinger cat animated on a quantum computer

Time evolution of the Schrodinger cat: probability distribution W(x) at -3.14 < x < 3.14 is shown for different number of map iterations t, changing along y-axis from t=0 (top) to t=180 (bottom). Here for the double well map K=0.04, a=1.6 and hbar = 4 x 3.1415/N with N=32. Quantum computation is done with 6 qubits and and noisy gates of noise strength eps = 0.02, and 2090 gates per one map iteration. At t=0 initial coherent packet is located at x=-a.
From Ref. 131

http://xxx.lanl.gov/abs/quant-ph/0202113


   
Quantum fractal survivor

Quantum fractal eigenstate (Husimi function) with minimal decay rate in the open quantum kicked rotator with the chaos parameter K=7; probability is absorbed outside of box size N=59049, kick strength k=N/4.
From Ref. 97 (Physica D 131 (1999) 311)

http://xxx.lanl.gov/abs/cond-mat/9710118

   
Quantum chaos & quantum computers

Quantum computer melting induced by the coupling between qubits. Color represents the level of quantum eigenstate entropy Sq (blue - minimal Sq=0, red - maximal Sq=11) for 12 qubits. Vertical axis gives the coupling strength, horizontal one gives the energy of computer eigenstate.
From Ref. 107 (1999)

http://xxx.lanl.gov/abs/quant-ph/9909074

   
Dynamical turbulent flow on the Galton board with friction (video)

See the color animated turbulent flow from Ref. 120 (2001) at

http://xxx.lanl.gov/abs/cond-mat/0103515


   
Delocalization of two-particle ring
near the Fermi level of 2d Anderson model

Probability distributions f and f_d for TIP in 2d disordered lattice of size L=40, and interaction of radius R=12 and width dR = 1. Left column, one-particle probability f for W=8V: ground state at U=0 (top); ground state with binding energy E = -1.05 V at U=-2V (middle); coupled state with E = -0.19 V at U=-2V (bottom). Right column: f for coupled state, compare to bottom left, at W=12V and U=-2V with E = -0.19 V(top); inter-particle distance probability f_d related to the middle left case (middle); f_d related to the bottom left case (bottom). All data are shown for the same disorder realisation.
From Ref. 110 (2000)

http://xxx.lanl.gov/abs/cond-mat/0002296

   
Generalized Cooper problem in the vicinity of Anderson transition

Probability distributions for two interacting particles in the 3d Anderson model at the ground state. Probability is projected on (x,y)-plane: one particle probability f_p for Hubbard interaction U=-4 V (left column), interparticle distance probability f_pd for U=-4 V (centrum column), f_p for U=0 (right column); the disorder strength is W/W_c=1.1 (upper line), W/W_c=0.5 (middle line), W/W_c=0.3 (bottom line); W_c=16.5 V is the critical disorder for Anderson transition at half filling. All data are given for the same realisation of disorder for the system size L=16. Upper line corresponds to the insulating noninteracting phase while two others are in the metallic one at U=0.
From Ref. 109 (1999)

http://xxx.lanl.gov/abs/cond-mat/9911461

   
Poincare recurrences: quantum and classical fractals

Quantum Husimi function in the kicked rotator with absorption at time t=100 (top left); 5000 (middle left), 3x10^5 (bottom left); right top (t=100) and middle (t=5000) are classical probabilities, number of levels N=3^8 , kick strength k=N/4, chaos parameter K=7; right bottom shows Husimi function for N=3^6, t=10^7.
From Ref. 100 (Phys. Rev. Lett. 82 (1999) 524)

http://xxx.lanl.gov/cond-mat/abs/9807145

 
Quantum fractals in hydrogen atom

Probability distribution in action-phase plane (y,x) for classical (left) and quantum (right) atom in a microwave field after 50 microwave periods, initial level n=1200.
From Ref. 108 (1999)

http://xxx.lanl.gov/abs/cond-mat/9911200
 

   
Quantum ergodicity in rough billiards

Transition from localization to Shnirelman ergodicity on energy surface (n,l) for level number N =2250, l_max=95 and M=20; shown are the absolute amplitudes of one eigenstate: a) localization for D=20, b) Wigner ergodicity for D=80 and c) Shnirelman ergodicity for D=1000.
From Ref. 92 (Phys. Rev. Lett. 79 (1997) 1833)

http://xxx.lanl.gov/abs/cond-mat/9807145