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Volumn 80, Issue 16, 2009, Pages

Spectral singularities in a non-Hermitian Friedrichs-Fano-Anderson model

(1)  Longhi, Stefano a  

a CNR   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords


EID: 72649084319     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.80.165125     Document Type: Article
Times cited : (127)

References (83)
  • 1
    • 34547309949 scopus 로고    scopus 로고
    • 10.1088/0034-4885/70/6/R03
    • C. M. Bender, Rep. Prog. Phys. 70, 947 (2007). 10.1088/0034-4885/70/6/R03
    • (2007) Rep. Prog. Phys. , vol.70 , pp. 947
    • Bender, C.M.1
  • 2
    • 34547362946 scopus 로고    scopus 로고
    • 10.1088/1751-8113/40/32/R01
    • P. Dorey, C. Dunning, and R. Tateo, J. Phys. A 40, R205 (2007). 10.1088/1751-8113/40/32/R01
    • (2007) J. Phys. A , vol.40 , pp. 205
    • Dorey, P.1    Dunning, C.2    Tateo, R.3
  • 3
    • 72649089094 scopus 로고    scopus 로고
    • arXiv:0810.5643 (unpublished).
    • A. Mostafazadeh, arXiv:0810.5643 (unpublished).
    • Mostafazadeh, A.1
  • 6
    • 5444266131 scopus 로고    scopus 로고
    • 10.1023/B:CJOP.0000044002.05657.04
    • M. V. Berry, Czech. J. Phys. 54, 1039 (2004). 10.1023/B:CJOP.0000044002. 05657.04
    • (2004) Czech. J. Phys. , vol.54 , pp. 1039
    • Berry, M.V.1
  • 11
    • 18744381334 scopus 로고    scopus 로고
    • 10.1088/0305-4470/38/21/L04
    • B. F. Samsonov, J. Phys. A 38, L397 (2005). 10.1088/0305-4470/38/21/L04
    • (2005) J. Phys. A , vol.38 , pp. 397
    • Samsonov, B.F.1
  • 13
    • 0010465259 scopus 로고
    • 10.1016/0370-1573(94)90177-5;
    • W. D. Heiss, Phys. Rep. 242, 443 (1994) 10.1016/0370-1573(94)90177-5
    • (1994) Phys. Rep. , vol.242 , pp. 443
    • Heiss, W.D.1
  • 22
    • 48249137769 scopus 로고    scopus 로고
    • 10.1088/1751-8113/41/24/244018
    • M. Müller and I. Rotter, J. Phys. A 41, 244018 (2008). 10.1088/1751-8113/41/24/244018
    • (2008) J. Phys. A , vol.41 , pp. 244018
    • Müller, M.1    Rotter, I.2
  • 23
    • 66749184063 scopus 로고    scopus 로고
    • 10.1103/PhysRevLett.102.220402
    • A. Mostafazadeh, Phys. Rev. Lett. 102, 220402 (2009). 10.1103/PhysRevLett.102.220402
    • (2009) Phys. Rev. Lett. , vol.102 , pp. 220402
    • Mostafazadeh, A.1
  • 24
    • 33947257382 scopus 로고    scopus 로고
    • 10.1088/0305-4470/39/43/008
    • A. Mostafazadeh, J. Phys. A 39, 13495 (2006). 10.1088/0305-4470/39/43/008
    • (2006) J. Phys. A , vol.39 , pp. 13495
    • Mostafazadeh, A.1
  • 25
    • 72649095826 scopus 로고    scopus 로고
    • arXiv:0908.2876 (unpublished).
    • Z. Ahmedar, arXiv:0908.2876 (unpublished).
    • Ahmedar, Z.1
  • 27
    • 70349513783 scopus 로고    scopus 로고
    • 10.1103/PhysRevA.80.032711
    • A. Mostafazadeh, Phys. Rev. A 80, 032711 (2009). 10.1103/PhysRevA.80. 032711
    • (2009) Phys. Rev. A , vol.80 , pp. 032711
    • Mostafazadeh, A.1
  • 30
    • 2842515744 scopus 로고
    • 10.1103/PhysRev.124.1866
    • U. Fano, Phys. Rev. 124, 1866 (1961). 10.1103/PhysRev.124.1866
    • (1961) Phys. Rev. , vol.124 , pp. 1866
    • Fano, U.1
  • 31
    • 2842617037 scopus 로고
    • 10.1103/PhysRev.124.41
    • P. W. Anderson, Phys. Rev. 124, 41 (1961). 10.1103/PhysRev.124.41
    • (1961) Phys. Rev. , vol.124 , pp. 41
    • Anderson, P.W.1
  • 37
    • 0003964324 scopus 로고
    • Plenum Press, New York
    • G. D. Mahan, Many-Particle Physics (Plenum Press, New York, 1990), pp. 272-285.
    • (1990) Many-Particle Physics , pp. 272-285
    • Mahan, G.D.1
  • 40
    • 0000175796 scopus 로고    scopus 로고
    • 10.1103/PhysRevB.57.12127;
    • N. Stefanou and A. Modinos, Phys. Rev. B 57, 12127 (1998) 10.1103/PhysRevB.57.12127
    • (1998) Phys. Rev. B , vol.57 , pp. 12127
    • Stefanou, N.1    Modinos, A.2
  • 42
  • 44
  • 56
    • 0035981064 scopus 로고    scopus 로고
    • 10.1103/PhysRevLett.87.270405;
    • A. G. Kofman and G. Kurizki, Phys. Rev. Lett. 87, 270405 (2001) 10.1103/PhysRevLett.87.270405
    • (2001) Phys. Rev. Lett. , vol.87 , pp. 270405
    • Kofman, A.G.1    Kurizki, G.2
  • 61
  • 62
    • 29644434662 scopus 로고    scopus 로고
    • 10.1103/PhysRevB.72.165330
    • L.-L. Lin, Z.-Y. Li, and B. Lin, Phys. Rev. B 72, 165330 (2005). 10.1103/PhysRevB.72.165330
    • (2005) Phys. Rev. B , vol.72 , pp. 165330
    • Lin, L.-L.1    Li, Z.-Y.2    Lin, B.3
  • 64
    • 33846359224 scopus 로고    scopus 로고
    • 10.1103/PhysRevA.74.063826
    • S. Longhi, Phys. Rev. A 74, 063826 (2006). 10.1103/PhysRevA.74.063826
    • (2006) Phys. Rev. A , vol.74 , pp. 063826
    • Longhi, S.1
  • 65
    • 34249885323 scopus 로고    scopus 로고
    • 10.1140/epjb/e2007-00143-2
    • S. Longhi, Eur. Phys. J. B 57, 45 (2007). 10.1140/epjb/e2007-00143-2
    • (2007) Eur. Phys. J. B , vol.57 , pp. 45
    • Longhi, S.1
  • 66
    • 33748533452 scopus 로고    scopus 로고
    • 10.1103/PhysRevLett.97.110402;
    • S. Longhi, Phys. Rev. Lett. 97, 110402 (2006) 10.1103/PhysRevLett.97. 110402
    • (2006) Phys. Rev. Lett. , vol.97 , pp. 110402
    • Longhi, S.1
  • 70
    • 28844460677 scopus 로고    scopus 로고
    • 10.1103/PhysRevA.72.063405
    • M. Miyamoto, Phys. Rev. A 72, 063405 (2005). 10.1103/PhysRevA.72.063405
    • (2005) Phys. Rev. A , vol.72 , pp. 063405
    • Miyamoto, M.1
  • 71
    • 72649103622 scopus 로고    scopus 로고
    • For Im (Ea) =0, we recover the Hermitian limit of the FFA Hamiltonian. In this case a divergence of the resolvent for z→ E0, obtained from Eq. with V (E0) =0, corresponds to a bound state embedded into the continuum (see, e.g., Refs.) rather than to a spectral singularity of H.
    • For Im (Ea) =0, we recover the Hermitian limit of the FFA Hamiltonian. In this case a divergence of the resolvent for z→ E0, obtained from Eq. with V (E0) =0, corresponds to a bound state embedded into the continuum (see, e.g., Refs.) rather than to a spectral singularity of H.
  • 72
    • 72649099333 scopus 로고    scopus 로고
    • In fact, if z were a real-valued root of Eq. outside the interval (E1, E2), according to Eq. one would have Σ (z) =Δ (z) because V (z) =0. Hence, Σ (z) turns out to be real valued. To satisfy Eq. the condition Im (Ea) =0 must be thus satisfied. This means that a real-valued root z of Eq.necessarily requires H to be Hermitian.
    • In fact, if z were a real-valued root of Eq. outside the interval (E1, E2), according to Eq. one would have Σ (z) =Δ (z) because V (z) =0. Hence, Σ (z) turns out to be real valued. To satisfy Eq., the condition Im (Ea) =0 must be thus satisfied. This means that a real-valued root z of Eq. necessarily requires H to be Hermitian.
  • 73
    • 72649096602 scopus 로고    scopus 로고
    • Since the divergence of G (z) at z= E0 on the continuous spectrum occurs when z approaches E0 solely from one side (either from the top or from the bottom) of the complex plane, E0 does not belong to the point spectrum of H; rather it is a spectral singularity. In fact, if E0 were an eigenvalue of H corresponding to a square-integrable eigenfunction | E0 , denoting by | E0† the eigenfunction of the adjoint H† corresponding to the same eigenvalue and taking in Eq. |χ = | E0† and |φ = | E0 , one would obtain Gχ,φ (z) =ger; | E0 / (z- E0). Since E0† | E0 is finite, it would then follow that Gχ,φ (z) should diverge when both z= E0 +i 0+ and z= E0 -i 0+.
    • Since the divergence of G (z) at z= E0 on the continuous spectrum occurs when z approaches E0 solely from one side (either from the top or from the bottom) of the complex plane, E0 does not belong to the point spectrum of H; rather it is a spectral singularity. In fact, if E0 were an eigenvalue of H corresponding to a square-integrable eigenfunction | E0, denoting by | E0† the eigenfunction of the adjoint H† corresponding to the same eigenvalue and taking in Eq. |χ = | E0† and |φ = | E0, one would obtain Gχ,φ (z) = E0† | E0 / (z- E0). Since E0† | E0 is finite, it would then follow that Gχ,φ (z) should diverge when both z= E0 +i 0+ and z= E0 -i 0+.
  • 74
    • 72649104961 scopus 로고    scopus 로고
    • For a featureless continuum, for which Δ (E) and V (E) are smooth functions of E, the resonance curve has a Lorentzian shape and the quantum system, initially prepared in state |a, would decay into the continuum following a (nearly) exponential decay law with lifetime 1/ [πV (Ea)] (Weisskopf-Wigner or Breit-Wigner approximation). See also the discussion in Sec.
    • For a featureless continuum, for which Δ (E) and V (E) are smooth functions of E, the resonance curve has a Lorentzian shape and the quantum system, initially prepared in state |a, would decay into the continuum following a (nearly) exponential decay law with lifetime 1/ [πV (Ea)] (Weisskopf-Wigner or Breit-Wigner approximation). See also the discussion in Sec..
  • 75
    • 72649101069 scopus 로고    scopus 로고
    • We assume here that the spectrum of H is purely continuous, i.e., we assume that there are not bound states (outside or embedded in the continuum). In this case, for the Hermitian FFA model the decay of the survival probability P (t) is always complete.
    • We assume here that the spectrum of H is purely continuous, i.e., we assume that there are not bound states (outside or embedded in the continuum). In this case, for the Hermitian FFA model the decay of the survival probability P (t) is always complete.
  • 76
    • 72649088221 scopus 로고    scopus 로고
    • The proper determination of the square root on the right-hand side of Eq.must be chosen such that Im [Σ (z=E±i 0+)] =πV (E), according to Eq.
    • The proper determination of the square root on the right-hand side of Eq. must be chosen such that Im [Σ (z=E±i 0+)] =πV (E), according to Eq..
  • 79
    • 72649096218 scopus 로고    scopus 로고
    • More precisely, far from the lattice boundary a wave packet of the form cn (t) = □dkQ (k) exp [-ikn-iE (k) t], with spectrum Q (k) narrow at around k= k0 (0< k0 <π), propagates along the lattice with a group velocity vg =dn/dt=-2 κ0 sin k0 <0, i.e., the wave packet is incident onto the lattice boundary. Conversely, a wave packet formed by the superposition cn (t) = □dkQ (k) exp [ikn-iE (k) t], with spectrum Q (k) narrow at around k= k0, propagates along the lattice with a group velocity vg =2 κ0 sin k0 >0, i.e. it is reflected from the lattice edge.
    • More precisely, far from the lattice boundary a wave packet of the form cn (t) = □dkQ (k) exp [-ikn-iE (k) t], with spectrum Q (k) narrow at around k= k0 (0< k0 <π), propagates along the lattice with a group velocity vg =dn/dt=-2 κ0 sin k0 <0, i.e., the wave packet is incident onto the lattice boundary. Conversely, a wave packet formed by the superposition cn (t) = □dkQ (k) exp [ikn-iE (k) t], with spectrum Q (k) narrow at around k= k0, propagates along the lattice with a group velocity vg =2 κ0 sin k0 >0, i.e. it is reflected from the lattice edge.
  • 80
    • 72649087705 scopus 로고    scopus 로고
    • At the coalescent point, the resolvent G (z) has a second-order pole at z=0.
    • At the coalescent point, the resolvent G (z) has a second-order pole at z=0.


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