1. Unusual magnetotransport properties of NbSe 3 single crystals at low temperature A.A.Sinchenko MEPhI, Moscow, Russia Yu.I.Latyshev, A.P.Orlov IRE RAS, Moscow, Russia P.Monceau CRTBT-CNRS Grenoble, France

2. Outline Magnetoresistance of NbSe 3 : history In-plain negative magnetoresistance Quantum linear magnetoresistance Phase of Shubnikov-de Haas oscillations at different field orientations Summary

3. R.M.Fleming, et al, PRB,1978J.Richard, et al, PRB, 1987 Solid line - function  0 /(  2 sin 2  +cos 2  ) 1/2  =1/8 P.Monceau, et al, J.Phys.C, 1978 R.M.Fleming, et al, PRB, 1978 M.P.Everson, et al, PRB, 1985 R.V.Coleman, et al, PRL, 1985 J.Richard, et al, PRB, 1987 O.Laborde, et al, EPL, 1987 M.P.Everson, et al, PRB, 1987 P.Monceau, J.Richard, PRB, 1988 T.M.Tritt, et al, PRB, 1988, R.V.Coleman, et al, PRB, 1990

4. R.M.Fleming, et al, PRB,1978J.Richard, et al, PRB, 1987 Solid line - function  0 /(  2 sin 2  +cos 2  ) 1/2  =1/8 P.Monceau, et al, J.Phys.C, 1978 R.M.Fleming, et al, PRB, 1978 M.P.Everson, et al, PRB, 1985 R.V.Coleman, et al, PRL, 1985 J.Richard, et al, PRB, 1987 O.Laborde, et al, EPL, 1987 M.P.Everson, et al, PRB, 1987 P.Monceau, J.Richard, PRB, 1988 T.M.Tritt, et al, PRB, 1988, R.V.Coleman, et al, PRB, 1990

5. Results 5.3  m I B I B a*a* c b

6. Results 5.3  m I B I B a*a* c b 2.7  m

7. Results 5.3  m I B I B a*a* c b Results 5.3  m I B I B a*a* c b 2.7  m 1.3  m

8. Results 5.3  m I B I B a*a* c b Results 5.3  m I B I B a*a* c b 2.7  m Results 5.3  m I B I B a*a* c b Results 5.3  m I B I B a*a* c b 2.7  m 1.3  m 1.1  m

9. Results 5.3  m I B a*a* c b Results 5.3  m I B I B a*a* c b Results 5.3  m I B I B a*a* c b 2.7  m Results 5.3  m I B I B a*a* c b Results 5.3  m I B I B a*a* c b 2.7  m 1.3  m 1.1  m

10. Results 5.3  m I B I B a*a* c b Results 5.3  m I B I B a*a* c b Results 5.3  m I B I B a*a* c b 2.7  m Results 5.3  m I B I B a*a* c b Results 5.3  m I B I B a*a* c b 2.7  m 1.3  m 1.1  m

11. Results Temperature evolution d=1  m

12. Results

13. B max

14. Results B max B max is independent on d. At T=4.2 K  B max  =0.12 T.

15. Results B max B max is independent on d. At T=4.2 K  B max  =0.12 T. at B=0.31 T region of transition to quantum limit

16. Results B max B max is independent on d. At T=4.2 K  B max  =0.12 T. at B=0.31 T region of transition to quantum limit Sharp drop of resistance in transition region 0.1-0.4 T

17. Results B max B min B max is independent on d. At T=4.2 K  B max  =0.12 T. at B=0.31 T region of transition to quantum limit Sharp drop of resistance in transition region 0.1-0.4 T

18. Results B max B min B max is independent on d. At T=4.2 K  B max  =0.12 T. at B=0.31 T region of transition to quantum limit A=const Larmor diameter corresponding to B min D  d Sharp drop of resistance in transition region 0.1-0.4 T

19. Results B max B min B max is independent on d. At T=4.2 K  B max  =0.12 T. at B=0.31 T region of transition to quantum limit A=const Larmor diameter corresponding to B min D  d d c =5-8  m Sharp drop of resistance in transition region 0.1-0.4 T

20. Results B max B min B max is independent on d. At T=4.2 K  B max  =0.12 T. at B=0.31 T region of transition to quantum limit A=const Larmor diameter corresponding to B min D  d d c =5-8  m Sharp drop of resistance in transition region 0.1-0.4 T

21. Quantum lenear magnetoresistance [AA..Abrikosov, J.Phys.A (2003); PRB (1998), PRB (1999)] Landau bands in an isotropic model for moderate magnetic field. Many bands contain electrons Landau bands in the quantum limit. Only the lowest band contains electrons. The conditions: NbSe 3 In the case of small electron groups (layer materials with small electron and hole pockets) in strong (  1) magnetic field perpendicular to the field resistivity:   1 at H=0.03 T

22. Below quantum limit, D>d R B2R B2 I B I B I B I B I B I B I B I B I B Quantum limit, D>d negative magnetoresistance Quntum limit, D<d Quantum linear magbetoresistance e

23. Angle dependence of magnetoresistance IIIIIIIII B

24. IIIIIIIII B

25. Only parallel to c-axis component of magnetic field determines the orbital motion of carriers

26. momenta of pockets carriers are predominantly oriented along b-axis (chain direction) of crystal (Sinchenko, Latyshev, Monceau, 2005) Angle dependence of magnetoresistance IIIIIIIII B (d>dc)(d>dc) axially symmetric case:

27. Summary The negative in-plain magnetoresistance has been observed in NbSe 3 single crystals with the sample thickness less some critical value that is determined by the Larmor diameter at magnetic field corresponding to transition to the quantum limit. The momenta of carriers that are not condensed in CDW are predominantly oriented along the conducting chains.