Angulaire Matériel 2: 'md-entrée" n'est pas un élément connu

Ce qui me manque ici? Devrait md-input être chargées individuellement dans le module fichier?

Cela fonctionne:

<md-input-container>
  <input mdInput name="username" placeholder="Username" [(ngModel)]="username" #name="ngModel" required>          
</md-input-container>

Toutefois, il échoue:

<md-input placeholder="amount" align="end">
  <span md-prefix>$&nbsp;</span>
  <span md-suffix>.00</span>
</md-input>

avec l'erreur suivante:

Unhandled Promise rejection: Template parse errors:
'md-input' is not a known element:
1. If 'md-input' is an Angular component, then verify that it is part of this module.
2. If 'md-input' is a Web Component then add "CUSTOM_ELEMENTS_SCHEMA" to the '@NgModule.schemas' of this component to suppress this message. ("
  </div>
  <div>
    [ERROR ->]<md-input placeholder="amount" align="end">
      <span md-prefix>$&nbsp;</span>

app.le module.ts

import { NgModule }      from '@angular/core';
import { CommonModule }   from "@angular/common";
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from "@angular/forms";
import { MaterialModule } from "@angular/material";

import { AppComponent }  from './app.component';

import "hammerjs";

@NgModule({
  imports:      [ 
    CommonModule,
    BrowserModule, 
    FormsModule,
    MaterialModule.forRoot() 
  ],
  declarations: [ AppComponent ],
  bootstrap:    [ AppComponent ]
})
export class AppModule { }