title: Nonequilibrium transitions in quantum optical systems

authors: Drummond, Peter David

abstract: The topic of this thesis is a theoretical study of nonequilibrium transitions and quantum statistical properties of nonlinear quantum optical systems driven by an external radiation source. In certain limiting cases, a comparison is made between these transitions and the phase transitions found in equilibrium physical systems.
In chapters one and two, the mathematical tools are introduced. In operator terms, the time development is described by a Markovian master equation in the interaction picture. This is equivalent to a corresponding time development equation or Fokker-Planck equation in a vector space of c-numbers. In order to deal with the type of Fokker-Planck equation that results, we introduce a quantum classical correspondence resulting in a distribution function over a complex phase-space, which is a generalisation of the Glauber-Sudarshan P-function.
In chapter three this is applied to a model of a coherently driven mode with nonlinear dispersion and absorption. We find in the limit of zero temperature, that the spectrum is symmetric relative to the input frequency, and an exact solution is obtained for the distribution function. For a detuned driving field and nonlinear dispersion, optical bistability can occur. 
In chapter four a model of sub/second harmonic generation is introduced. This has several non-equilibrium transitions, including dispersive optical bistability, and bistable behaviour with coherent phase-locked input to both modes. Exact solutions occur in the limit of zero temperature and adiabatic elimination of one mode. In both chapters three and four, steady-state photon anti-bunching occurs with an absorptive nonlinearity. 
In chapter five we include interactions between the radiation mode and a fluorescent atomic system. In this case different behaviour occurs depending on the relative decay rates of the individual atoms and of the radiation mode. In the case of a high-Q interferometer, the atomic variables can be adiabatically eliminated. Both dispersive and absorptive bistability can occur. We show by analytic and numerical calculations (in the case of inhomogeneous broadening) that dispersive operation has advantages in requiring a lower atomic density and input field to observe bistability. When the input field has Gaussian (rather than coherent) photon statistics, there is no bistability, but enhanced photon bunching occurs. 
Finally, there is a different type of behaviour when the field mode decays rapidly and can be adiabatically eliminated. Within the cooperation lifetime the system can be described by a J²-invariant Hamiltonian, giving the special case of only collective damping. The result is a new type of critical point transition in the thermodynamic limit, with the appearance of a family of solutions like Lotka-Volterra cycles for a coherent driving field above threshold.

text: Nonequilibrium transitions in quantum optical systems The topic of this thesis is a theoretical study of nonequilibrium transitions and quantum statistical properties of nonlinear quantum optical systems driven by an external radiation source. In certain limiting cases, a comparison is made between these transitions and the phase transitions found in equilibrium physical systems.
In chapters one and two, the mathematical tools are introduced. In operator terms, the time development is described by a Markovian master equation in the interaction picture. This is equivalent to a corresponding time development equation or Fokker-Planck equation in a vector space of c-numbers. In order to deal with the type of Fokker-Planck equation that results, we introduce a quantum classical correspondence resulting in a distribution function over a complex phase-space, which is a generalisation of the Glauber-Sudarshan P-function.
In chapter three this is applied to a model of a coherently driven mode with nonlinear dispersion and absorption. We find in the limit of zero temperature, that the spectrum is symmetric relative to the input frequency, and an exact solution is obtained for the distribution function. For a detuned driving field and nonlinear dispersion, optical bistability can occur. 
In chapter four a model of sub/second harmonic generation is introduced. This has several non-equilibrium transitions, including dispersive optical bistability, and bistable behaviour with coherent phase-locked input to both modes. Exact solutions occur in the limit of zero temperature and adiabatic elimination of one mode. In both chapters three and four, steady-state photon anti-bunching occurs with an absorptive nonlinearity. 
In chapter five we include interactions between the radiation mode and a fluorescent atomic system. In this case different behaviour occurs depending on the relative decay rates of the individual atoms and of the radiation mode. In the case of a high-Q interferometer, the atomic variables can be adiabatically eliminated. Both dispersive and absorptive bistability can occur. We show by analytic and numerical calculations (in the case of inhomogeneous broadening) that dispersive operation has advantages in requiring a lower atomic density and input field to observe bistability. When the input field has Gaussian (rather than coherent) photon statistics, there is no bistability, but enhanced photon bunching occurs. 
Finally, there is a different type of behaviour when the field mode decays rapidly and can be adiabatically eliminated. Within the cooperation lifetime the system can be described by a J²-invariant Hamiltonian, giving the special case of only collective damping. The result is a new type of critical point transition in the thermodynamic limit, with the appearance of a family of solutions like Lotka-Volterra cycles for a coherent driving field above threshold.

year: 1979

title: Sexual assaults on gay and bisexual men: Barriers to reporting to the police

authors: Patlakas, Peter

subjects: sexual assault

abstract: Sexual assault is a matter of public concern that affects many individuals globally, regardless of their gender and sexual orientation.  With many survivors of sexual assaults choosing not to report their victimisation to police, it appears that prevalence rates based on reports made to the police represent only a fraction of the actual occurrence of assaults.  This is especially the case where assaults on gay and bisexual men are concerned.  This study examined the barriers gay and bisexual male survivors of sexual assaults face in reporting their victimisation to the police.
This study aimed to address a lack in New Zealand based research on the topic and develop an overall representation of the various barriers these survivors may encounter, as well as solutions for their reduction.  This was achieved by conducting semi-structured interviews with six service providers functioning as key informants and four gay/bisexual male survivors of sexual assault.  Interviews were recorded and transcribed for thematic analysis.  The qualitative software NVivo was used to allow for the development and organisation of themes and subthemes from the interview data collected.  Four themes were identified pertaining to barriers: personal, social, institutional, and abuse-specific.  Personal and social barriers were more readily recognised than those within the institutional and abuse-specific themes.  A fifth theme, the reduction theme, emerged in relation to suggestions for decreasing barriers.
The following eight barrier areas were identified within the personal barrier theme: defence mechanisms, cognitive mindset, revisiting, knowledge, emotions, privacy/confidentiality, past experience, and mental health.  The social theme consisted of nine barrier areas: family, queer community, support, culture and religion, homosexuality and gender, myths, judgement, homophobia and prejudice, and location and environment.  Seven barrier areas were identified within the institutional theme: poor responses, services and counselling, cons to reporting, the law, court dynamics, limitations, and police.  The abuse-specific barrier theme consisted of nine barrier areas: time, need for proof, victim-perpetrator relationship, age, drugs and alcohol, disclosure of details, consent issues, report scrutiny, and labelling and defining.
Finally, six areas were identified pertaining to the reduction of barriers: services, youth, police, information, reporting process, and societal attitudes.  Many of the suggestions for reduction methods, such as increasing police training and services offered within the queer community, were seen to be beneficial, yet they may still be subject to various difficulties in their implementation, such as funding concerns.
Queer-specific barrier aspects were deemed important to account for in order to develop a comprehensive understanding of the topic.  Various linkages between barriers also emerged, effectively making a decision to report to the police even harder for survivors.  A case study based on one of the survivors interviewed helped to illustrate this complex weaving of barriers.
Further research is needed to examine these barriers on deeper levels, particularly in terms of addressing any differences between youth and adult survivors.  The results of this study serve as the first step in developing the foundation to bring information on this topic to the forefront of New Zealand research in the area.

text: Sexual assaults on gay and bisexual men: Barriers to reporting to the police Sexual assault is a matter of public concern that affects many individuals globally, regardless of their gender and sexual orientation.  With many survivors of sexual assaults choosing not to report their victimisation to police, it appears that prevalence rates based on reports made to the police represent only a fraction of the actual occurrence of assaults.  This is especially the case where assaults on gay and bisexual men are concerned.  This study examined the barriers gay and bisexual male survivors of sexual assaults face in reporting their victimisation to the police.
This study aimed to address a lack in New Zealand based research on the topic and develop an overall representation of the various barriers these survivors may encounter, as well as solutions for their reduction.  This was achieved by conducting semi-structured interviews with six service providers functioning as key informants and four gay/bisexual male survivors of sexual assault.  Interviews were recorded and transcribed for thematic analysis.  The qualitative software NVivo was used to allow for the development and organisation of themes and subthemes from the interview data collected.  Four themes were identified pertaining to barriers: personal, social, institutional, and abuse-specific.  Personal and social barriers were more readily recognised than those within the institutional and abuse-specific themes.  A fifth theme, the reduction theme, emerged in relation to suggestions for decreasing barriers.
The following eight barrier areas were identified within the personal barrier theme: defence mechanisms, cognitive mindset, revisiting, knowledge, emotions, privacy/confidentiality, past experience, and mental health.  The social theme consisted of nine barrier areas: family, queer community, support, culture and religion, homosexuality and gender, myths, judgement, homophobia and prejudice, and location and environment.  Seven barrier areas were identified within the institutional theme: poor responses, services and counselling, cons to reporting, the law, court dynamics, limitations, and police.  The abuse-specific barrier theme consisted of nine barrier areas: time, need for proof, victim-perpetrator relationship, age, drugs and alcohol, disclosure of details, consent issues, report scrutiny, and labelling and defining.
Finally, six areas were identified pertaining to the reduction of barriers: services, youth, police, information, reporting process, and societal attitudes.  Many of the suggestions for reduction methods, such as increasing police training and services offered within the queer community, were seen to be beneficial, yet they may still be subject to various difficulties in their implementation, such as funding concerns.
Queer-specific barrier aspects were deemed important to account for in order to develop a comprehensive understanding of the topic.  Various linkages between barriers also emerged, effectively making a decision to report to the police even harder for survivors.  A case study based on one of the survivors interviewed helped to illustrate this complex weaving of barriers.
Further research is needed to examine these barriers on deeper levels, particularly in terms of addressing any differences between youth and adult survivors.  The results of this study serve as the first step in developing the foundation to bring information on this topic to the forefront of New Zealand research in the area.

year: 2013

title: Engaging and working with Maori? Effective practice for psychologists in education

authors: Glynn, Ted

subjects: New Zealand

abstract: I believe this whakatauki captures the reflective processes I am now engaged in, as I assess where I have come from and where I am going, as a second-generation pakeha of Irish descent, who completed postgraduate degrees in Psychology and Education in New Zealand and Canada, and who has been engaging and working with Māori in the field of education for many years.

text: Engaging and working with Maori? Effective practice for psychologists in education I believe this whakatauki captures the reflective processes I am now engaged in, as I assess where I have come from and where I am going, as a second-generation pakeha of Irish descent, who completed postgraduate degrees in Psychology and Education in New Zealand and Canada, and who has been engaging and working with Māori in the field of education for many years.

year: 2008