Sharing variables between two methods in a controller?

I have two methods auth and notes and I want to share a variable between them.

require 'rest_client'

class MynotesController < ApplicationController
  obj.instance_eval('@parsedToken')

  def auth
    username = params[:name]
    password = params[:password]
    if (username != 0)
      token = RestClient.post 'candidate.apiary.io/login', :params => {:username => username, :password => password}
      @parsedToken = ActiveSupport::JSON.decode(token) 
    end
  end

  def notes

  end


end

What should I do if i want to access @parsedToken in the notes method?