Departament de Fìsica i Enginyeria Nuclear, Campus Nord B4-B5, Universitat Politècnica de Catalunya,

Barcelona, Spain

G.E. Astrakharchik, J. Boronat, O.N.Osychenko, Yu.E. Lozovik, Y. Lutsyshyn

Grenoble, 7th of July, 2010

MONTE CARLO STUDY OF QUANTUM PHASE DIAGRAM OF

RYDBERG ATOMS WITH REPULSIVE 1/r6 INTERACTION

MOTIVATION

INTERACTION POTENTIAL

MODEL HAMILTONIAN

MONTE CARLO METHODS

GUIDING WAVE FUNCTION

CLASSICAL CRYSTAL

0.000 0.002 0.004 0.006 0.008 0.0103.45

3.50

3.55

3.60

3.65

E / N

BCC FCC HCP

1 / N

QUANTUM ZERO-TEMPERATURE PHASE TRANSITION

8 10 12 14 16200

400

600

800

1000

solidgas

E / E0

gas solid classical FCC solid

r30

transition

TYPICAL NUMBERS

LOW TEMPERATURE

0 1 2 3 4 50

1

2

3

r / r0

g2(r)/2

T/E0=0.2

N = 32 N = 108 N = 864 N = 1372

HIGH TEMPERATURE

0 1 2 3 4 50

1

2

3 T/E0=0.3

N = 32 N = 108 N = 864 N = 1372

g2(r)/2

r / r0

PEAK IN STRUCTURE FACTOR

100 10001

10

100

1000S(k

peak)

N

T/E0 = 0.1

T/E0 = 0.2

T/E0 = 0.22

T/E0 = 0.25

T/E0 = 0.3

T/E0 = 0.4

T/E0 = 0.5

TEMPERATURE GAS-SOLID TRANSITION

3.2 3.4 3.6 3.8 4.00

2

4

6

8

10

p(E)

T=0.20 T=0.21 T=0.22 T=0.23 T=0.24 T=0.25 T=0.26 T=0.27 T=0.28 T=0.29 T=0.30

E

PHASE DIAGRAM

0 5 10 15 200.0

0.1

0.2

0.3

cr3

0 11

TC 0.23 E

0

normal gas

crystalsuperfluid gas

T/E0

r3

0

FCC vs HCP

0 1 2 3 4 5

-2x10-4

0

2x10-4

EFCC

- EHCP

0

WHICH MASS/KINETIC ENERGY?

CONCLUSIONS

THANK YOU VERY MUCH FOR YOUR ATTENTION!

INTERACTION POTENTIAL