메뉴 건너뛰기




Volumn 59, Issue 9, 1999, Pages 6449-6474

Extreme type-ii superconductors in a magnetic field: A theory of critical fluctuations

Author keywords

[No Author keywords available]

Indexed keywords


EID: 0001750188     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.59.6449     Document Type: Article
Times cited : (112)

References (106)
  • 22
    • 33646606052 scopus 로고
    • The concept of vortex lattice melting transition was suggested by G. Eilenberger, Phys. Rev. 153, 584 (1967). In the context of high-temperature superconductors, early theoretical studies include Ref. 8;
    • (1967) Phys. Rev. , vol.153 , pp. 584
    • Eilenberger, G.1
  • 24
    • 0000482071 scopus 로고
    • Phys. Rev. BM. A. Moore, 39, 136 (1989);
    • (1989) , vol.39 , pp. 136
    • Moore, M.A.1
  • 28
    • 85035210950 scopus 로고
    • Phys. Rev. BZ. Tes̆anović, 44, 12 635 (1991).
    • (1991) , vol.44 , pp. 12
    • Tes̆anović, Z.1
  • 29
    • 0041363730 scopus 로고
    • The existence of such a transition was established experimentally in P. L. Gammel, et al., Phys. Rev. Lett. 59, 2592 (1987);
    • (1987) Phys. Rev. Lett. , vol.59 , pp. 2592
    • Gammel, P.L.1
  • 30
    • 85038918566 scopus 로고
    • Phys. Rev. Lett.P. L. Gammel61, 1666 (1968);
    • (1968) , vol.61 , pp. 1666
    • Gammel, P.L.1
  • 31
    • 6244262168 scopus 로고
    • Phys. Rev. Lett.H. Safar, et al., 69, 824 (1992).
    • (1992) , vol.69 , pp. 824
    • Safar, H.1
  • 38
    • 85038892205 scopus 로고    scopus 로고
    • The main results of the present theory should also be applicable, with appropriate modifications, to uniformly rotating superfluid helium.
    • The main results of the present theory should also be applicable, with appropriate modifications, to uniformly rotating superfluid helium.
  • 39
    • 85038900063 scopus 로고    scopus 로고
    • H. Enriquez, et al., cond-mat/9801233 (unpublished), and references therein.
    • Enriquez, H.1
  • 41
    • 0344837566 scopus 로고
    • Phys. Rev. BJ. R. Clem, 43, 7837 (1991);
    • (1991) , vol.43 , pp. 7837
    • Clem, J.R.1
  • 47
    • 0008873294 scopus 로고    scopus 로고
    • These authors identify a new transition line, (Formula presented) separating from the melting line at low fields. It is natural to expect (Formula presented) in the thermodynamic limit [S. Ryu (private communication)]. I thank S. Ryu and D. Stroud for discussions on this point. Note, however, that these authors found a finite helicity modulus along the field below their (Formula presented) in contrast to Ref. 23
    • S. Ryu and D. Stroud, Phys. Rev. Lett. 78, 4629 (1997).These authors identify a new transition line, (Formula presented) separating from the melting line at low fields. It is natural to expect (Formula presented) in the thermodynamic limit [S. Ryu (private communication)]. I thank S. Ryu and D. Stroud for discussions on this point. Note, however, that these authors found a finite helicity modulus along the field below their (Formula presented) in contrast to Ref. 23.
    • (1997) Phys. Rev. Lett. , vol.78 , pp. 4629
    • Ryu, S.1    Stroud, D.2
  • 48
    • 85038949605 scopus 로고    scopus 로고
    • (Formula presented) is the vector potential associated with a given configuration of s vortices, with unit fluxes attached. In the notation of Ref. 9, (Formula presented) would correspond to (Formula presented) where (Formula presented) is the phase of the gauge transformation used in that paper. An explicit form of (Formula presented) is, however, not uniquely determined by the positions of s vortices: one must also specify the positions of branch cuts across which the phase changes from 0 to 2π. The present formulation eliminates this unnecessary complication since (Formula presented) itself is uniquely determined for any given configuration of s vortices.
    • (Formula presented) is the vector potential associated with a given configuration of s vortices, with unit fluxes attached. In the notation of Ref. 9, (Formula presented) would correspond to (Formula presented) where (Formula presented) is the phase of the gauge transformation used in that paper. An explicit form of (Formula presented) is, however, not uniquely determined by the positions of s vortices: one must also specify the positions of branch cuts across which the phase changes from 0 to 2π. The present formulation eliminates this unnecessary complication since (Formula presented) itself is uniquely determined for any given configuration of s vortices.
  • 50
    • 85038928425 scopus 로고    scopus 로고
    • There is, however, no simple correspondence at the level of correlation functions. The equivalence between the two representations, Eqs. (1) and (2), works only for the full partition functions and not at the level of individual configurations. This is clear since, for a given configuration of Z (1) with (Formula presented) vortex lines “percolating” across the system along (Formula presented) we cannot tell which ones are field induced and which are thermally generated. All we know is that each configuration must have at least (Formula presented) of such vortex lines. For example, this precludes a direct connection between Φ and the original (Formula presented)
    • There is, however, no simple correspondence at the level of correlation functions. The equivalence between the two representations, Eqs. (1) and (2), works only for the full partition functions and not at the level of individual configurations. This is clear since, for a given configuration of Z (1) with (Formula presented) vortex lines “percolating” across the system along (Formula presented) we cannot tell which ones are field induced and which are thermally generated. All we know is that each configuration must have at least (Formula presented) of such vortex lines. For example, this precludes a direct connection between Φ and the original (Formula presented)
  • 52
    • 0001652225 scopus 로고    scopus 로고
    • The effective long-range interaction between s vortices vanishes at (Formula presented) and is quite weak right below (Ref. 9). If we view s vortices as world lines of some relativistic quantum particles with very light effective mass, this quantum system with arbitrary weak long-range interactions is most likely in the “superfluid” ground state right below (Formula presented) This implies the vanishing of the helicity modulus, in accordance with our original assumption (ii) (Sec. II). Note that a quantum system of nonrelativistic (and, therefore, less likely to wind in the (Formula presented) plane) 2D bosons with a weak, and even rather strong, Coulomb-type long-range interaction is known to conform to this expectation; see H. Nordberg and G. Blatter, Phys. Rev. Lett. 79, 1925 (1997), and references therein.
    • (1997) Phys. Rev. Lett. , vol.79 , pp. 1925
    • Nordberg, H.1    Blatter, G.2
  • 53
    • 0000713065 scopus 로고
    • A similar nonrelativistic system with London-Biot-Savart-type long-range interaction of variable strength also appears to have a superfluid ground state when this interaction is weak; M. V. Feigel’man, V. B. Geshkenbein, L. B. Ioffe, and A. I. Larkin, Phys. Rev. B 48, 16 641 (1993).
    • (1993) Phys. Rev. B , vol.48 , pp. 16
    • Feigel’man, M.V.1    Geshkenbein, V.B.2    Ioffe, L.B.3    Larkin, A.I.4
  • 55
    • 24844435748 scopus 로고
    • Phys. Rev. BY. H. Li and S. Teitel, 49, 4136 (1994).
    • (1994) , vol.49 , pp. 4136
    • Li, Y.H.1    Teitel, S.2
  • 56
    • 0001297392 scopus 로고    scopus 로고
    • A. E. Koshelev, Phys. Rev. B 56, 11 201 (1997). This reference presents a lucid summary of main problems in the field and also considers the effects of disorder and layering.
    • (1997) Phys. Rev. B , vol.56 , pp. 11
    • Koshelev, A.E.1
  • 58
    • 85038915620 scopus 로고    scopus 로고
    • Extreme anisotropy and potential finite “mass terms” have been considered in Ref. 9. For example, footnote 20 of that paper considers the possibility of a finite helicity modulus (Formula presented) immediately below (Formula presented)
    • Extreme anisotropy and potential finite “mass terms” have been considered in Ref. 9. For example, footnote 20 of that paper considers the possibility of a finite helicity modulus (Formula presented) immediately below (Formula presented)
  • 59
    • 85038943937 scopus 로고    scopus 로고
    • As will be discussed later in the text, the Φ transition in the gauge theory (4) is governed by an isotropic critical point. However, with (Formula presented) and, potentially, finite (Formula presented) and/or Chern-Simons terms, the same transition could be governed by an anisotropic critical point, with a different set of critical exponents in (Formula presented) and (Formula presented) directions and correspondingly different details of critical thermodynamics and transport.
    • As will be discussed later in the text, the Φ transition in the gauge theory (4) is governed by an isotropic critical point. However, with (Formula presented) and, potentially, finite (Formula presented) and/or Chern-Simons terms, the same transition could be governed by an anisotropic critical point, with a different set of critical exponents in (Formula presented) and (Formula presented) directions and correspondingly different details of critical thermodynamics and transport.
  • 60
    • 85038957299 scopus 로고    scopus 로고
    • “Perturbed” comes with quotation marks since, even though the magnetic field enters Eq. (4) through a small parameter (Formula presented) this perturbation is strongly relevant and it immediately destabilizes the zero-field (“neutral”) 3D (Formula presented) critical point.
    • “Perturbed” comes with quotation marks since, even though the magnetic field enters Eq. (4) through a small parameter (Formula presented) this perturbation is strongly relevant and it immediately destabilizes the zero-field (“neutral”) 3D (Formula presented) critical point.
  • 68
    • 25044444823 scopus 로고    scopus 로고
    • Phys. Rev. Lett.I. F. HerbutZ. Tes̆anović 78, 980 (1997), and references therein.
    • (1997) , vol.78 , pp. 980
    • Herbut, I.F.1    Tes̆anović, Z.2
  • 72
    • 77956950163 scopus 로고
    • North-Holland, Amsterdam C. J. Gorter
    • R. P. Feynman, in Progress in Low Temperature Physics, edited by C. J. Gorter (North-Holland, Amsterdam, 1964), Vol. 1, p. 17.
    • (1964) Progress in Low Temperature Physics , vol.1 , pp. 17
    • Feynman, R.P.1
  • 79
    • 0030173978 scopus 로고    scopus 로고
    • For parallels between critical behavior of high-temperature superconductors and superfluid (Formula presented) see T. Schneider, Physica B 222, 374 (1996), and references therein.
    • (1996) Physica B , vol.222 , pp. 374
    • Schneider, T.1
  • 80
    • 0000697590 scopus 로고    scopus 로고
    • J. M. Singer, et al., Phys. Rev. B 54, 1286 (1996) discuss the evolution of superconducting behavior from the BSC limit to that of preformed pairs.
    • (1996) Phys. Rev. B , vol.54 , pp. 1286
    • Singer, J.M.1
  • 84
    • 0032473335 scopus 로고    scopus 로고
    • Recent numerical simulations provide strong support for the “inverted 3D (Formula presented)” behavior: P. Olsson and S. Teitel, Phys. Rev. Lett. 80, 1964 (1998).
    • (1998) Phys. Rev. Lett. , vol.80 , pp. 1964
    • Olsson, P.1    Teitel, S.2
  • 85
    • 5844251674 scopus 로고
    • In general, liquid-to-solid phase transitions in 3D tend to be associated with unstable critical points and have a discontinuous, first-order characters; see S. A. Brazovski, I. E. Dzyaloshinski, and A. R. Muratov, Sov. Phys. JETP 93, 1110 (1987).
    • (1987) Sov. Phys. JETP , vol.93 , pp. 1110
    • Brazovski, S.A.1    Dzyaloshinski, I.E.2    Muratov, A.R.3
  • 86
    • 0028378616 scopus 로고
    • For a discussion specific to type-II superconductors, see Ref. 28 and Z. Tes̆anović, Physica C 220, 303 (1994).
    • (1994) Physica C , vol.220 , pp. 303
    • Tes̆anović, Z.1
  • 87
    • 85038959595 scopus 로고    scopus 로고
    • Note that (Formula presented) is not excluded at higher fields.
    • Note that (Formula presented) is not excluded at higher fields.
  • 88
    • 85038901091 scopus 로고    scopus 로고
    • Unlike the mean-field-based approach including only the field-induced London vortex lines, where the strength of this interaction is set by the mean-field amplitude squared of (Formula presented)
    • Unlike the mean-field-based approach including only the field-induced London vortex lines, where the strength of this interaction is set by the mean-field amplitude squared of (Formula presented)
  • 89
    • 85038901125 scopus 로고    scopus 로고
    • Equation (11) for (Formula presented) differs from the estimate reported in Ref. 9 in two ways: first, the previous estimate was made for the weakly coupled layered case and, second, it was based on the mean-field approximation to Eq. (2). In contrast, the present expression (11) is exact, provided (Formula presented) is specified.
    • Equation (11) for (Formula presented) differs from the estimate reported in Ref. 9 in two ways: first, the previous estimate was made for the weakly coupled layered case and, second, it was based on the mean-field approximation to Eq. (2). In contrast, the present expression (11) is exact, provided (Formula presented) is specified.
  • 91
    • 85038956214 scopus 로고    scopus 로고
    • This fundamental anisotropy is present even for (Formula presented) (Formula presented) and is set by (Formula presented) The value of (Formula presented) along the (Formula presented) line [more precisely, for (Formula presented) is a universal ratio of the gauge theory scenario.
    • This fundamental anisotropy is present even for (Formula presented) (Formula presented) and is set by (Formula presented) The value of (Formula presented) along the (Formula presented) line [more precisely, for (Formula presented) is a universal ratio of the gauge theory scenario.
  • 92
    • 4244027369 scopus 로고
    • While the rescaling procedure described here is a straightforward generalization of the familiar (Formula presented) rescaling of anisotropy, it does contain one salient point: the rescaled gauge theory looks just like the original Eq. (4) but with the Φ-dependent part isotropic, (Formula presented) (Formula presented) and (Formula presented) (Formula presented) However, the gauge is different: instead of the original Coulomb gauge (Formula presented) we now have (Formula presented) This is dealt with by introducing a gauge transformation: (Formula presented) and (Formula presented) where (Formula presented) is a regular phase defined so that the new gauge potential (Formula presented) satisfies the Coulomb gauge condition, i.e., (Formula presented) Such gauge transformation is both perfectly justified and desirable. It is justified because, even though our fictitious electrodynamics (4) is always defined in a specific gauge and does not possess the local gauge freedom of its real namesake, its free energy is still invariant under gauge transformations. It is desirable since the Coulomb gauge ensures that Φ (or (Formula presented) in the anisotropic case) can be used as a true physical order parameter of our Φ transition: see T. Kennedy and C. King, Phys. Rev. Lett. 55, 776 (1985). Related issues involving gauge transformations are discussed in Ref. 9. In the isotropic case (Formula presented) in Eq. (1)] none of these niceties are necessary and we can stay in the Coulomb gauge throughout. The fundamental anisotropy of the gauge theory, Eq. (4), expressed as (Formula presented) (Formula presented) always remains.
    • (1985) Phys. Rev. Lett. , vol.55 , pp. 776
    • Kennedy, T.1    King, C.2
  • 93
    • 85038886397 scopus 로고    scopus 로고
    • One naively expects the range of fields over which (Formula presented) is universal to be smaller than the corresponding range for (Formula presented) the melting line is first order and involves a nonuniform low-temperature state.
    • One naively expects the range of fields over which (Formula presented) is universal to be smaller than the corresponding range for (Formula presented) the melting line is first order and involves a nonuniform low-temperature state.
  • 94
    • 85038964601 scopus 로고    scopus 로고
    • The exponent p is assumed to have the same value, (Formula presented) throughout the Φ-ordered phase. We can show that this is the case in the regime where the average size of vortex loops and s vortex overhangs is (Formula presented) and we assume that it remains true everywhere below (Formula presented) This is consistent with our physical expectation that the long-wavelength limit of the Φ-ordered phase can be related to a suitably defined “line liquid,” in the sense of Nelson (Ref. 8). An alternative possibility, that of p being a continuously varying exponent, changing from (Formula presented) far below (Formula presented) to (Formula presented) as we approach (Formula presented) appears less likely in view of the overall picture painted by the gauge theory scenario. For example, the Φ-ordered state of Eq. (4) has a true long-range order and is not a critical phase with continuously varying exponents.
    • The exponent p is assumed to have the same value, (Formula presented) throughout the Φ-ordered phase. We can show that this is the case in the regime where the average size of vortex loops and s vortex overhangs is (Formula presented) and we assume that it remains true everywhere below (Formula presented) This is consistent with our physical expectation that the long-wavelength limit of the Φ-ordered phase can be related to a suitably defined “line liquid,” in the sense of Nelson (Ref. 8). An alternative possibility, that of p being a continuously varying exponent, changing from (Formula presented) far below (Formula presented) to (Formula presented) as we approach (Formula presented) appears less likely in view of the overall picture painted by the gauge theory scenario. For example, the Φ-ordered state of Eq. (4) has a true long-range order and is not a critical phase with continuously varying exponents.
  • 96
    • 85038964150 scopus 로고    scopus 로고
    • “Vortex tachyons” denote infinite vortex paths that traverse the system along x or y direction without winding along the z axis. Thus, in the boson analogy, they travel longer intervals across “space” ((Formula presented) plane) than along “time” (z axis (Formula presented)
    • “Vortex tachyons” denote infinite vortex paths that traverse the system along x or y direction without winding along the z axis. Thus, in the boson analogy, they travel longer intervals across “space” ((Formula presented) plane) than along “time” (z axis (Formula presented)
  • 97
    • 85038900233 scopus 로고    scopus 로고
    • Principle, however, such a phase could result in a new transition line between (Formula presented) and (Formula presented) at least in a certain window of material parameters.
    • In principle, however, such a phase could result in a new transition line between (Formula presented) and (Formula presented) at least in a certain window of material parameters.
  • 99
    • 0039746413 scopus 로고    scopus 로고
    • For a useful summary of various anisotropy effects, see E. Sardella, Phys. Rev. B 53, 14 506 (1996), and references therein.
    • (1996) Phys. Rev. B , vol.53 , pp. 14
    • Sardella, E.1
  • 100
    • 85038929916 scopus 로고    scopus 로고
    • The same would be true for the LL-based theories, if uncritically extended to the (Formula presented) limit.
    • The same would be true for the LL-based theories, if uncritically extended to the (Formula presented) limit.
  • 101
    • 85038962447 scopus 로고    scopus 로고
    • Eventually, for extremely low fields, the effect of electromagnetic screening (i.e., finite (Formula presented) becomes important and (Formula presented) as (Formula presented) (Ref. 8
    • Eventually, for extremely low fields, the effect of electromagnetic screening (i.e., finite (Formula presented) becomes important and (Formula presented) as (Formula presented) (Ref. 8).
  • 102
    • 85038960429 scopus 로고    scopus 로고
    • A. K. Nguyen and A. Sudbø (unpublished and private communication).
    • A. K. Nguyen and A. Sudbø (unpublished and private communication).
  • 103
    • 85038901570 scopus 로고    scopus 로고
    • The author is grateful to Prof. A. Sudbø and Dr. A. K. Nguyen for numerous discussions and the opportunity to see their unpublished numerical results.
    • Also, see S.-K. Chin, A. K. Nguyen, and A. Sudbø, cond-mat/9809115 (unpublished).The author is grateful to Prof. A. Sudbø and Dr. A. K. Nguyen for numerous discussions and the opportunity to see their unpublished numerical results.
    • Nguyen, A.K.1    Sudbø, A.2


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.